The Stovebolt Site Forums The Shop Area Engine Shop engine switch

Hi, I am thinking of getting a 250 to replace my 216 for my 48 5 window 1ton. However I have a few questions before i buy the engine.
1. How difficult is it to put this engine in? will it fit with the mounting brackets that are allready in for my 216? Or am i going to have to have some fabrication done.
2. will the transmission in my truck work with the bigger more powerful 250 or should I also buy the transmission he is selling with it.

I am currently in iraq, and my push rods went out right before the Army PCS'd me to Hawaii. My Truck is in oklahoma And i will probably pay a friend of the family to do this for me while i am out here. I just want to have an idea of the labor so i can compensate him for it.

It is extensive modifications. It,s almost the same as putting a v-8 except you don,t have the steering gear interference to contend with. You would have to get a crossmember from a 54 to support the bell housing. You would need to use a side motor mount kit or crossmember. The trans might fit. There are some variations in the bearing retainer mount hole in the bell housings. You can,t use the later trans unless you change rear ends. I wouldn,t recomend doing it unless you do it yourself & have a lot of time on your hands.

Another thing to consider is titling issues. Since most states used the engine number as the VIN prior to 56, if you change the engine the numbers on the title will not be on the truck any longer. As long as you own the vehicle or any title transfer is in-state you'll probably never have a problem. However if you sell the truck out of state and an inspection is required before the new owner can title it in their state, they will have a problem titling the truck without jumping through some hoops. Just something to keep in mind. Questions about titling issues caused by that very condition come up here a LOT.

Tiny:
would that same issue come up if you blew the original engine and had to replace it with another 216? It would have a different number on it as well. :confused: Or would the fact that it was a 216 make the difference?

The issue would be the same, the numbers don't match. I think that's why they eventually stopped using engine numbers for titling a vehicle. Every state should have a process for resolving the issue but everyone who changes the engine on a pre 56 vehicle needs to be aware that they may be creating a problem if they ever decide to sell it. If you're one of the fortunate who lives in one of the states that used the serial number on the data plate, and the data plate is still there, you won't have a problem.

ok so,
That doese sound complicated, and i would hate to do that to that man. Any Ideas what engines would easily fit into my 48 chevy. I am trying to get it to go at least 65 or 70, as i would like it to become a daily driver

The 235 1954 & up is the easiest swap. There is alot of info in the tech section & previous posts on this. There is an adapter out now to handle the water pump difference. All your bell housing clutch & trans. fit from the old engine. You will need to change rear ends to drive at highway speeds. The 1 ton is geared really low. You can find a center section from a 69-72 with 4.11 gears & use large tires.

If you want to change your engine and it is the original with the numbers on it, most trucks that age have had the engine replaced and the numbers are not original anyway, you can go to the DMV and have the cab number verified along with the orginal engine number. Explain to them you are going to replace the engine and want the truck registered by the cab number. They will probably want to see a bill of sale for the new engine.

Almost every old truck I have had, I have been through this because the engine either was not original or there were mistakes with the numbers.

Not a big deal.

To get the speeds you want, you should change the rear end along with the engine. The engine will be happier at a lower RPM and you will not think your engine is about to blowup when you are trying to get out of the way of a big rig on the freeway.

okay so this one will sound a little dumb. but when you say change the rear end what exactly do you mean? transmission? chassis? im pretty green

The gears in the differential on a 1-ton are 5.14 to 1. The differential is the round section of the rear axle visible from behind the truck looking forward under the bed.

While updating the motor might improve your top speed, with the current gears the problem is you will be turning the motor real fast. With the 216 going 60 to 70 is too fast to run that motor for any length of time.

Change to a 250 and it is likely to survive longer at that speed, but it will still be turning real fast. And that remains true no matter how big or modern the replacement motor might be.

Change the rear gears to 4.11 and the 216 will have trouble moving a heavy load, but the truck will manage highway speeds more readily.

Changing to an overdrive type transmission can achive the same kind of thing. An overdrive is usually about 30% meaning if it runs 45 before it will run 60 with the OD.

Best answer is probably to both swap to 4.11 gears in the rear, and run something like a T-5 overdrive 5-speed transmission. Then put the 250 in front of that, and while you won't have the same load moving grunt it started with, it will be real drivavle when empty and able to deal with some load.

What size tires do you plan to run? The stock 19 inch wheels limit your choices. If you are running smaller wheels that does affect your tire choices and the final ratio. Shorter tires will slow the truck down.

A 1-ton has an open type driveline, so you don't have to change the transmission and driveline to make some of the changes suggested. A 250 or similar motor (230 or 292) will require a bellhousing change, and that does impact the bellhousing crossmember. Since these motors side mount instead of front mount, it might be easier to use an aftermarket transmission crossmember rather that replacing the bellhousing crossmember. But that only works if you swap to a transmission that can be mounted that way...

This whole thing can be complicated, and rather than trying to detail every option it would be less confusing if you made a few of the choices, and then asked for the relevant details.

Several things,
You probably have 7.50x17" tires now.
I would suggest 8R19.5 tires on used 19.5 wheels from an older bread truck, or new wheels from Rickson Truck if you can't easily find used ones.
The 8R19.5 tires are about 32" outside, ans that's as big as you can fit easily on your truck, bigger tires, the faster you go.

I agree, you should have 5.14 gears in the rear now. You will need something faster to get to 70 mph. Try this site, it is helpful for figuring speeds. http://www.drivetraindirect.com/t_gear_calculator.htm Figure for a 235 or 261 your at your cruising speed, say 70 or whatever, your engine should be about 2,400 rpm, any faster and it won't last very long, slower and you don't have power for the hills. Whatever engine you do choose the cruising rpm should be about 100 or 200 over the rpm where the engine makes its peak torque.

From my figuring, you need 4.11 gears and a o.73 overdrive, or no overdrive and 3.54 gears.
For gears faster than 4.11, or 3.90 if you are really lucky, you need a entirely different rear.

A stock 235 from about 55 or later will just be enough power to go 70, but not haul much at that speed. The easiest swap for more power is a 261.
Any more power and it's not a real easy swap.

OK, suppose you figure out how to go fast, now you need to stop. Without a load and with a dual circuit master cylinder conversion your brakes should be fine with 70 mph, any more and you should consider better brakes.

You have a lot to figure out, and lots of work if you want to take your 1 ton up to 70 mph.
I have done some upgrades to my 52 1 ton, check out the pictures on the link below.

Grigg

Interesting that two of my three single wheel 1-tons have 19, yes 19 inch wheels. That's a '51 and a '54, one a Chevy and one a GMC. My other single wheel AD 1-ton has 16 inch wheels but it clearly has aftermarket wheels.

However the '54 (Chevy) Assembly Manual lists 17 inch as the proper size.

I don't know where the 19 inch wheels on my two came from, but they look original and I'd suggest you know your tire size so you can accurately calculate speed at RPM.

You did not say if your oneton is a dual rear wheel or a single rear wheel. This is what I did with a 55.2 dual rear wheel oneton.

292 I6 with a stock 4 sp. I replaced the stock rear axle with one from a early 70s 3/4 ton. It was the high GVW with the large brakes. This rear end was from an automatic trans truck. I am not sure what the ratio was but most likely 4.10 or maybe 3.73. This pickup rear end was close to the stock rear end in width. I replaced the wheel studs with longer ones for the dual wheels and changed the spring mounts. It worked out very nice.

If you have a oneton pickup this will not work well as the rear end will most likely be too wide.

WOw lots of answers. and more questions.
My truck is a single rear wheel. The tires are original. so whatever size came on the 48. my truck seems to have had the luxery upgrade from the factory (chrome grill, window trim, drivers arm rest, etc.) I dont know if that would have come with a different tire size other then the standard though.
As far as hauling goese, as long as it will carry a few army duffle bags full of gear that is all i need. I am thinking of trying to find a 261 to replace the 216. My truck also has a 4 on the floor.
if that helps

one more thing slighly off topic. I see a lot of references to 216's being babbit pounders what doese that mean?

The 216 "Babbitt pounder" is what you should have stock. The bearings are Babbitt, and not easily replaced like modern insert bearings. Modern bearings still have a thin coating of Babbitt, or a similar alloy. It's just the old ones are harder to work on and don't last as long unless you keep them adjusted, but that's a lot of work.
When they are out of adjustment they quickly "pound" themselves out, as in once they get a little loose they quickly get really loose.

Grigg