The Stovebolt Site Forums The Shop Area Engine Shop Swap out a good 216 for a used 261?

The original 216 in my '51, 3600 truck is in pretty good shape. The side cover leaks a bit but I've replaced the front and rear main seals and I don't mind adding a bit of makeup oil occasionally. It doesn't smoke or make any odd noises and it starts and runs just fine. It's a add gas, check the oil and go sorta rig.

Well, I've been considering a 261 upgrade even-though I'm pretty happy with the lit'l 216. A bit more ump would be nice when running in the hills or against a headwind. All that said I just stumbled across a '59 261 in a shop that was pulled from a old wrecker 10 years ago when the owner wanted a V8. Engine has been in a corner of the shop since then. Represented as ran fine when pulled. Price is $200.

I'm thinking pull plugs, squirt in a little oil, if it turns over pay the man and set it in my shops corner while I assemble the odds and ends for the swap. From following other threads I know the water pump will be an issue, I may need to swap the crank pulley for belt compatibility but can anyone speak to motor mounts, exhaust, anyway I can (without breaking the bank) keep my foot starter?

It does seem a bit foolish to pull a perfectly good original 216 but nobody ever said I wasn't foolish

Picture of the engine, looks to still have a carb.

More info, I haven't seen the engine yet, just the one photo. I'll look at it early next week. Other than will it turn over, one of the first items is determining if it's actually a 261 or a 235. Guess I'll need to be armed with engine numbers and a few details for proper id'n in my head. Good thing is I should have good cell signal at the shop so it may be as easy as Googling the engine number.

RonR

I switched out a 216 for a 261 in a suburban. U can keep foot starter, use 216 bellhousing, motor mounts same unless front mounts are different. Use your 216 timing plate with lower mounting bolts if needed. Foot stomper hardware will transfer with Bellhousing. 216 starter and flywheel should switch over if I remember correctly.

200.00 is a great price.

U can get around water pump easy enough with adapter plate and short shaft pump.

I don’t see Captain bars in the picture, so it is likely a 235.

Find and post these codes.

Members here will then ID the engine for you.

I'm with Dave, can you post the block casting number?

Tim, If I've seen your page before it's been a while. Great resource and thanks for sharing.

I'll give the engine a good going over. Hopefully it's not rust locked. Since the oil fill cap is off the valve cover will need to pull the cover and check for dirt dabber mud houses along with mice dens. Then if it spins and since the starter is still on the bell housing I'm thinking it should be pretty easy to pull the plugs and do a quick compression test. Assuming the owner will allow. If it passes those checks it's coming home with me. Obviously I need to know if it's a 235 or 261 and will figure out those details later.

I might want to oil the valve stems, then tap each valve with a rubber hammer or 2 x 4 to make sure no stuck valves leading to bent pushrods.

Ed

I just replaced a 216 in my '53 1/2 ton with a 261 from a '57 model 2-ton. Hard to tell from that picture if you have a 235 or 261 there, but the engine code by the fuel pump and the cylinder head code by the manifolds will tell you what block/head you have. A few other members should weigh in soon about how to "wake up" an engine that has been sitting for a period of time, and how to properly check everything before you ever hit the starter.

(Editor's Note: Members *have* weighed in on that and we made a Tech Tip out of it Happy reading)

A few notes from my swap (I had my 261 rebuilt by an engine builder):

1. I used the water pump adaptor: https://www.ebay.com/itm/1955-1962-CHEVROLET-235-261-WATER-PUMP-ADAPTER/142578007830?hash=item21324fbf16:g:jz4AAOSwmBhaCNA7
2. I used the 216 bell housing and foot-starter hardware
3. The front of the 261 block had to be drilled for the front 216-style motor mount. Make sure to do this before you put the engine in the truck.
4. You'll need the starter from the 261, so I would have it tested and if necessary, rebuilt.
5. Electronic ignition is pretty nice to have. A fellow stovebolt member helped me with a 1980's 250 HEI distributor collar modification that allows it to work in a 261. I found a re-manufactured OEM unit on RockAuto for about $55, and bought the top portion of the distributor (cap, wires, coil etc) from Napa. The "aftermarket" units made in China appear to be cheaply made and unreliable.
6. Make sure you have the correct carb for that engine, whether its a 235 or 261. You can find measurements on this site that will help you confirm which carb you have and/or need. From your picture, it looks like the engine has a Rochester B. In my opinion and experience, those Rochesters suck. The 2 that I own are going to be thrown off of a bridge after I put my Zenith 228 on soon. From what I hear, a Carter YF or Zenith 228 is a great option for a 235 or 261, just get the right model number that was meant for that particular engine.
7. If you do end up rebuilding this 235/261, consult with a few of the members here about must-do items before you tear into it. There are some very helpful tips that will save you headaches later (such as using a rubber or even modify the block to accept a 1-piece rear main seal, instead of using the old 2-piece rope-style seal that could lead to a major oil leak. Don't ask me how I know about this issue...

Good info Patrick,
You can use the front mounting plate off the 216 on the 261 as well as the flywheel, clutch, clutch housing and starter if you want to stay 6 volt. Do not use the distributor from the 216 in the 261 because of the steel gear and cast cam incompatibility. Also use the early style water pump off the 216 with the adapter plate for correct fan placement, it will require drilling and tapping two holes in the 261 block but that is done easy enough.

Steve

A side story of course. After I had just gotten my original engine back from a complete overhaul my mechanic said, you know I think I have a 261 in the back room. But I am glad I can say it has the original engine and it has been fine for 36 years.

Just to echo the comments about the block casting numbers -- NEWS FLASH --

***** Not all 261's have Captain bars *****

The other thing is .... DON'T ORDER ANY PARTS UNTIL YOU KNOW BOTH THE CASTING CODE ***and**** the DATE of CASTING. It matters!


At any rate, if you find a 261 without captain bars, the casting code will tell you what it is -- either a block cast in 1954 or 1955, or a later block cast in the '54 mold. In the OP's case, if he's found a later 261 out of the '54 mold, then he's found a crate motor that was built as a replacement engine for the '54 and '55 first series trucks. What that further means is that it is a perfect upgrade engine for the AD trucks as it has the higher water pump position and fits in exactly without modification. So actually, for a pre '54 AD truck, the non-captain bar 261 is the one to have as it will require zero modifications to fit and work perfectly in your truck.

I pulled a perfectly fine 216 out of my 3804 and replaced it with a 261 -- it was a group effort and we made a pretty good tech tip out of it (read it). The other thing we learned was even though it seemed to run fine, you need to treat every unknown engine as a rebuildable core. It was making a particular noise at road speed that only Hotrod Lincoln could hear, and based on his recommendation, we pulled it back out and tore it down -- sure enough, the crankshaft and cam journals were heavily scored and number six piston had a few chunks missing out of it. Had I continued to run it, it probably would have catastrophically failed. Thanks Jerry!! Ended up having the crank ground and getting a new cam.

On mine, I used all the peripherals from my 216 (except the carburetor) to make it look like a 216, including the bell housing, flywheel, starter, generator, fuel pump, valve cover and distributor.

Sure, with care, the 216 can continue to run in your truck, especially the little trucks. But for the 3600 and 3800 trucks, at least with mine, driving in traffic or hilly conditions was problematic with the ole 216. Great engine, but not for a heavier truck in modern traffic -- especially with the HO52/72's original gearing. Oh yeah, so while I still hadthe 216 in my truck, I switched out the third member for the 4.11 gearing. Great, the 216 could now get me to 65 mph ... but the slightest hill or headwind, and we were back to 50. She huffed and puffed but holding speeds higher than 60 were pretty hard. Plus, accelerating from stop lights, or trying to pass anyone were exercises in futility. The 261 has reinvigorated my truck and has made it a lot more able to share the road with modern iron, if not also safer (people aren't doing stupid things to get around me). We will all support you if ou want to stay "original" but I wager you've already crossed that line somewhere else Why not at least make the truck driveable on modern roads?

If you do get the 261, do yourself a favor and tear it down before you install it. Chances are, if you don't, you may end up having to pull it back out to do it anyway. Worst case? You find nothing wrong and you slap it back together with new seals, bearings (why not, you have it apart anyway??) and gaskets and a whole lot of peace of mind.

One other lesson learned .... don't order new main bearings until you pull the old ones to see which style they are ... We talk about this one in the Tech Tip ... IF it is a later block cast in the '54 mold, it will probably be set up for the later bearings (dimples) rather than the early bearings (dowels). Not wanting to wait for a new bearing set to come in (and having everyone standing around my shop for a week ...), Jerry whipped out the drill and modified my block so now it will accept either style main bearings (which was nervewracking to say the least -- watching someone take a regular power drill to the crankshaft journals ... freehand ... but it worked!)

Just my opinion from having been there and done that.




Oh, and did I mention that not all 261's have captain bars??

"I pulled a perfectly fine 216 out of my 3804 and replaced it with a 261"

"I used all the peripherals from my 216 (except the carburetor) to make it look like a 216, including the bell housing, flywheel, starter, generator, fuel pump, valve cover and distributor."

Did you change the distributor gear to a later 235/261 gear?

If I could shake everyone's hand that's offered great advice on this thread I'd do it with a sincere "Thank You"! Since I can't, metaphorically speaking you'all just had a healthy handshake of Thanks!

John, don't know if you have a legal background but you laid out as logical and persuasive a case for making the change as I can imagine. Heck, I feel a bit dim witted for not having already made the upgrade.

Guess I need to double up on my monthly site usage payment

Tim -- Nope. Didn't have to. I remember asking Jerry about that and he gave me the reason why, in my particular instance, that wasn't a concern. You are right that it *is* a valid question, but I cannot recall why the answer was "no" for me. Apparently, you don't always have to change that gear ... You'd have to ask Jerry.

The only "tells" on my engine are the carburetor, the push rod cover and, of course, the casting codes Otherwise, you can't tell it from a 216. It fools a lot of people who think they know these old trucks.... Then again, there's a lot of people who look and would believe me if I told them it was a 6-71 Detroit ... (I had left over Alpine Green from my 6-71 project so I used that instead the right engine paint ... but hey, I saved $8.

Someone mentioned the timing gear cover ... That might be something to check. On my install, I inadvertently destroyed the timing cover on the 261 removing the harmonic balancer .... (Note: the bolts on the gear puller won't bottom out until after they've punctured the timing gear cover and hit the cam gear ... so be careful with the puller.) So I ended up having to use the 216 cover anyway.

Ron -- Not an attorney, but I've worked with enough of them over the years If you have a 261 out of the '54 mold, you've hit the home run. Keep the 216 in the truck and do a rebuild on the 261. Should be fun with no pressure. Then when it's ready, do the swap. It helps to invite truck buddies over -- especially ones who know more than you do about all of this (which is *all* of them in my case . When you're done, you will be amazed at how much more driveable you've made your truck without going crazy with V-8's, IFS, automatic trannies, rear axle swaps, wheels and tires, blah blah blah. I did do the Juliano's 3-pt seltbelt kit in my truck, though My gas tank is still in the cab and I'm happy with my multi-piece rims and bias plies (I *do* keep all of that in mind and drive conservatively while smoking my cigar

Oh, and did I mention my Huck Brakes? work just fine, thank you. It's not a Corvette so I don't try to drive it like one.

By the way, here are my casting codes -- They had us going at first -- a '54 mold engine, built in '59 ... Last image is my engine after reassembly with all the 216 goodies on it ready for the break in (but before final paint and installation in the truck). The only thing I don't like about this set up is that the 216 valve cover leaks and there's just not much you can do about it. Oh well.

Some of the auto sites I frequent will lock particularly informative threads in a easy to spot location, often calling them sticky's. Usually at the top of the appropriate forums subgroup. If we had that option this thread would qualify.

RonR

Forum Moderators have that option. It is used sparingly.

I recently swapped out a tired 216 with a freshly rebuilt 244 (235 bored 0.060" over) and the performance was noticeably improved.
I looked for a good rebuildable 261 but what I found was either non rebuildable or way out of my price range so I went with a 54 235. Everything improved and even though the 235 is highly modified it's avg'ing around 15.5 mpg while running with modern traffic.
Like John suggests, get it and rebuild it at your leisure while your 216 keeps purring on. Many parts will swap from the 216 and some you have to swap.
Depending upon your skill set, a total engine rebuild will run anywhere from $1500 - $3000. I farmed out the machine work and did my own reassembly then after breaking it in I let the engine sit a couple years before I did the swap.

As they say there's no replacement for displacement but keep in mind these Stovebolt engines are low rpm torquers, not high rpm screamers...

As Jerry says they're just glorified tractor engines LOL.

Good luck
Dave

I would echo the suggestion to tear down the engine before installation. I put in a nicely rebuilt 216 that had been sitting on a shop floor for many years. It turns out there was a mouse nest in the cooling jacket and the head got plugged and cracked.

If you have the space, a spare engine makes sense to me. I have a 235 on the floor just in case.

Ditto that spare engine on hand. I just went through the pain of rebuilding my 235. Had to buy a whole motor just to get a usable head. Which by the way is the hardest part. In the end , I figured I better start hoarding anything and everything 235.. I have a complete engine on a stand, sealed off under the bench now . I am still rooting more out of the weeds so to speak for stock.

Well, I now have another project, YeeHawaaaaa. Too many projects and too little time. The 261 is in the back of the ol '95 ..... Cummins 3500. We were barely able to load it with the collapsible lift the previous owner had. We were just able to get it into the bed far enough to close the tailgate. Sure made for a better ride.

Per Deve's GM Engine Casting Number list I have a 3733950 Chevrolet 55-57, 261. Where have I seen that number.....Oh, on Johns engine picts a few post above (Insert happy faces here).

Numbers are; just above the starter; CON L159

In front of the fuel pump, just above the pan; 3733950

On the head; 3836850 GM5

Pulled the carb and the intake/carb opening is 1.75"

Based on my recent new found knowledge I "think" I have a no Captains Bars, 261 cast in the '54 block mold as John described above. I didn't pull the valve cover or do a compression test or do any of the prepurchase checks mentioned but the engine just looks good. By looking in the oil hole in the valve cover I could that the valve train still has oily looking oil on it and not just a bunch of dried up crud. After I finish a couple or three pressing projects I'll start the assessment of my new to me 261 engine.

PS, if this isn't a hen's tooth of a 261 please let me down easy!!!

RonR

Ron,

Which of those codes make you think it is a 1954 engine/block?
If CON L159 is the block date casting code:
L = 12 = December
15 = 15th
9 = 1959
If I am incorrect, someone will post a correction.

My sources indicate the 3733950 block casting code was used from 1955-1957.

The 3836850 heads were used from 1956-1962.

What is the engine serial number and the head date casting code?

Tim, my "guess" is based on the information & images John posted above to include no captain bars, a 1959 casting date and the same casting
number, 3733950.

John said; “
At any rate, if you find a 261 without captain bars, the casting code will tell you what it is -- either a block cast in 1954 or 1955, or a later block cast in the '54 mold. In the OP's case, if he's found a later 261 out of the '54 mold, then he's found a crate motor that was built as a replacement engine for the '54 and '55 first series trucks. What that further means is that it is a perfect upgrade engine for the AD trucks as it has the higher water pump position and fits in exactly without modification. So actually, for a pre '54 AD truck, the non-captain bar 261 is the one to have as it will require zero modifications to fit and work perfectly in your truck.”

I rechecked for a serial number and can't see one. The attached image shows the area on the pan rail between the starter and distributor (the bolt on the right hand side of the image is a distributor hold down bolt).

Thanks for your help Tim, is there another location I might find the engine number. Will spend time tomorrow when I unload the engine looking at details with a bit more care than today's hurried agenda allowed.

RonR

John,

What color is that pale green paint you used on your engine? It looks similar to the color of the Jasper crate engine in my '61. I need to do some touch-ups.

-Kevin

No one has ever posted a documented GM paint code for green (or, yellow) USA 261 engines.

People have suggested these colors for green 261s:
Alpine "Detroit-Diesel" Green
John Deere Green
Plasti-Kote 225 Alpine Green
Dupli-Color Engine Enamel DE1618 Detroit Diesel Alpine Green

People have suggested these for yellow 261s:
12 oz. Farm Equipment John Deere Yellow Gloss Enamel Spray Paint
Daytona Yellow (from Cosmo)
"Edsel/Pacer" yellow (amtrakjoe)
VHT Yellow engine paint
Duplicolor Daytona Yellow engine paint
Rustoleum Daytona Yellow engine paint
Eastwood Yellow 650 degrees paint

Tim, not trying to be picky, but I believe "L" is November as they didn't use "I" (eye) because it looks to much like 1...am I wrong about this?

Mike B

Thanks, Mike

You are not being picky, if that is correct.

The Duplicolor Detroit Diesel is a nice color for the 261, fairly close in correct color. Plastic kote alpine color is the closest to the correct color that I can tell but plastic kote is no longer available. The detroit diesel green is in my link in my signiture.

I unloaded the 261 today. After a little closer look I'm cautiously encouraged. Pulled the valve cover and it was amaizingly clean along with the valvetrain. NO sludge. Also tapped the valves with a deadblow hammer and no stuck valves. Just to be on the safe side I squirted a generous amount of transmission fluid on the valve guides. Also pulled the plugs and they were all black from a rich condition but no signs of oil burning. I also squirted a few ozs of tranny fluid in the cylinders before reinstalling the spark plugs.

One odity that I recall reading about (HotRod Lincoln ?) was a crimped off vertical line under the valve cover. I'd be interested in hearing the "why" for that.

Paint, it appears to be original engine paint. If not the engine was hot tanked and then repainted. To get a true color I sprayed a bit of brake cleaner on one spot and the paint instantly looked new (green) and got sticky. Not sure what that means so far as kind of paint, or if it's a clue of factory paint.

I was going see if it'd spin over while the plugs were out but the crank bolt was missing in the harmonic balancer.

Water Pump, to my uneducated eye it appears the water pump is in the same location as the one on the 51's 216. Pretty tickled about that.

I'm generally a pretty optimistic person and currently I'm pretty happy with the possibilities of this engine. The proof will be in compression test and partial tear-down. Soon I hope.

If you referring to the image ending in 4027?

That is the crimped tube that feeds oil into the rocker arm assembly.

Do you want see documentation showing the differences in that fitting throughout many years?
I will post a link when I get to a real computer.

If you referring to the image ending in 4027?

Tim that's the one. Now that I look at it (again) it's part of the rocker arm assembly, the crimp struck me as owner inflicted and caught my attention. I’d already put the v cover back on when I noticed it on the picture. On a second look I understand.

Thanks,
RonR

RonR,

This page might help you ID your connecter/oiler?

Here is Pre 68 Dave's write-up on that/those parts.

Catching back up ... If there is no serial number stamped into the boss aft of the distributor (like mine), then that means it's probably a crate motor -- built as a replacement engine. Mine was built in '59 but out of the '54 mold -- to be sold as a replacement engine for someone with a '54 or '55 1st series who needed a new engine.

Kevin -- My engine paint is Detroit Diesel Alpine Green -- left over from my 6-71 days... Not meant to be a correct color -- just what I had at the time. Besides, it sounds cool to say it's a 2-61 ...

Thanks Tim, good info to know.

John, unless I'm misreading the tea leaves (which is always possible), my 261 is a 9 month younger brother to yours. A high water pump, no captain bars 261 with a '54 block cast in '59, what are the odds.

RonR

Tim,

I stand corrected...looking at some of your engine pictures today I saw an "I" (eye) on a date code, so I was wrong and you are right (again) "L" = Dec.

Mike B

What matters, Mike, is that WE get it right in the end, WE hope.

Helping people here is a group effort.

Ron,

Well that's good news, then! IF the casting number tells you it's the '54 mold, and the date code and the head casting number tell you '59, and there's no captain bars or serial number ... then yes, I think you have found the younger brother to mine and you will have a very easy swap. Now, the mistake I made was to order the older style main bearings. Because the block was built in 1959, they were already using the newer style bearings, so you will want to check to see which style main bearings it has before you order new ones. My guess is that it will have the newer style.

As a side note -- Over the weekend, I managed to catch up with the gang in Winchester, VA. This was my 261's first major road trip since the rebuild -- about 300 miles total, most of it at sustained highway speeds* ( did 70 MPH at one point, according to my GPS, probably on I-66). The engine ran flawlessly and did not use any oil (minimal drips). Once again, BIG thanks to Hotrod Lincoln in coaching us through a rebuild done *right.*

And seeing as how we honed the cylinders, we think this engine is a 262 now

* Have I mentioned my new Huck brakes and new set of 17-inch bias ply tires?

John, thanks for the information and advice. Not sure my upgrade will totally measure up to yours but I'm guessing it'll be well worth the effort. Several projects ahead of this one though. Why oh Why does it take so long to get things done these days. Oh yeah, I remember

Well, if *you* remember, share it with the rest of us ....

Every time I remember, I soon thereafter forget.