The Stovebolt Site Forums The Shop Area Engine Shop 235 what's the diff?

I've searched and I haven't located a thread that addresses my questions directly. I've read a lot of different opinions, but I am still in the dark.

I have a '51 3100 with a '54 235. Converted over to 12V. "Pearl" is used as a daily driver and has a 4 speed transmission which I believe (after reading the threads) is a SM420 (granny gear). Pearl has a top highway speed of roughly 57 mph (I am running 15" rims) and I want to coax as much out of my engine without stepping up to a V8. I would like to rebuild the 235 and introduce fuel injection (no info), a pertronix elctronic ignition (followed the thread) and swap the rear end (and transmission if necessary).
I've had the truck safety certified in BC, Canada. But in August, I will have to take it in for AirCare... I've got a feeling Pearl won't make it without a rebuild, as I've got a little bit of a miss in #6. Most wreckers in the area are a little shy of pre 80s truck stock and was hoping someone could offer a couple of solid suggestions I can pitch to them. ie: what make, what year, makes the easiest swap.
I am looking for a something with 3.40 or 3.55 gears which I hope can give me highway speeds. I believe I have a closed driveshaft and may have to look for a rear gear swap instead.
Looking for someone near Vancouver, BC that can put this all together for me?
PS! Looking forward to the 2008 cruise schedule

Hy deanomartini, how fast are you wanting to go, you could start by going up to taller 16" tires. Different suppliers have replacement higher speed gears for the stock rear end, you could try those two mods, and if you want still more speed you could swap in an overdrive transmission, hope that helps.

Your least expensive route would be to go with 16" wheels and a 3:55 R&P, and rebuild your engine. If you want to spend a lot more money, the options are endless.

Forget fuel injection... that engine doesn't have individual intake ports so even if you did find a way to add FI, the return wouldn't be worth the effort and expense. Add dual exhausts, electronic ignition and a small 4-barrel carb, and leave everything else stock.

It isn't so much that the same old questions become rather boring after a while about where can I get this or that. It is more about getting members and especially the newbies to use what we have to offer. Right at the very top Right Hand Side of this page is a SEARCH area. Over the length of time this site has been in operation and the thousands of questions about where to obtain needed parts I would expect that nearly everything most people are looking for has been covered.....so give the rest a break and do some looking on your own first. You'll probably find it if you ask in the proper manner. If you still can't find it then by all means ask away. We are here to help.

'''''''''a pertronix elctronic ignition (followed the thread) and swap the rear end (and transmission ).'''''

do the swap!!! DO a search on this subject in searches....
Want to know about swapping out a rear end.
and what to use Here's food for thought.... on 50’s chevy’s By: Jim Forbes


The 82-newer Camaros are wider than the older ones, so you should stick with the 70-81 models. The 75-79 Nova uses the same rear as these older Camaros, I believe. The 68-74 Nova chassis is the same as a 67-69 Camaro; the 75-79 Nova chassis is the same as the 70-81 Camaro. The 82-newer Camaros used the small 7.5" rear-end design that the 78-newer Malibu/Monte Carlo/regal/cutlass etc used, but it's quite a bit wider. Some of the 82-newer Camaros used different rear ends, such as the Dana 44, and some weird Australian rear-end. Of course, if you want to make sure, get out your tape measure and check yourself! I may be wrong.
Here's another one from Jim on the subject---- There are lots of rear ends available! Some fit better than others.

>>> For 6 lug rear ends, the 64-69 1/2 ton 2wd Chevy (and some GMC) trucks have a 12 bolt rear, about 60-61" wide (I measure them where the wheels bolt on). The 70 2wd and 70-81 4wd have a 6 lug 12 bolt that is a couple inches wider, but will fit under an Advanced Design or Task Force truck as long as you don't get too wild with wheel/tire width. The heavy duty models have a 2.75’’ brake shoe, that’s stopping power. The 12 bolt truck rear ends from the 60s usually had 3.70 gears, which is a bit much for extended highway driving at 75 mph. You can swap the differential carrier and ring/pinion gears from a later TRUCK or VAN 12 bolt, the 70s trucks usually had 3.08 or 3.40 gears. Of course, you'll need to know how to set up ring/pinion gears, bearing preload, and all that other neat stuff to do this.

These 60s truck 12 bolt rear ends are from coil spring trucks, so the perches are in the wrong place, and they have some extra stuff on the housing for a panhard bar, which you won't need with leaf springs. Most 60s GMC trucks, and some Chevys, had Dana 44 or Dana 60 rear ends, and leaf springs. These rear ends are 6 lug, about 60" wide, and will bolt into a Task Force truck (with some fudging, the perches are about 1/2" too far apart). The brakes use different parking brake cables, which is a problem, and the drums have a different offset. Gear ratios range from 3.21 to 3.92 normally, the 3.21 is found behind some GMC V-6 engines, and is a nice ratio for an old truck. The Dana 44 uses a standard Chevy 1310 yoke, but the Dana 60 uses a heavy duty yoke, which takes a larger 1350 series ujoint. A similar Dana 40 rear-end was available as an option in 59 Chevy trucks, equipped with positraction...rare, and with a 3.92 ratio. I have one of these rear ends; it was in my extended cab truck...I'm saving it for when I build a race truck (one of these years).
The 71 and newer 2wd trucks use a 5 lug 5" bolt pattern, same as the 71-76 full size cars. There is not much available in the way of matching front brake rotors that will fit an old truck, so this rear-end is not too popular a swap, unless you get the 70-up 4wd 6 lug axles. Chevy also used 10 or 12 bolt rear ends in lots of cars, in varying widths. The heavy duty models have a 2.75’’ brake shoe. A common one is the 61" wide 70s vintage Camaro/Chevelle/Nova (and clones) 8.5" rear-end. In Camaros/Novas it has leaf springs, but the perches won't work with old truck springs. In Chevelles, it has coil springs, with lots of extra brackets to cut off, and the cast in mounting "eyes" on top, where the upper control arm bushings fit. Wheel bolt pattern is 4.75", and there are front disk brake kits available to match, or you can use the 53-54 car front hubs/drums on the original 50s truck brakes, to get the same bolt pattern front/rear. This is a good rear-end for using in an old truck, the ratios are commonly 2.73-3.36, with higher gears available. The axle shafts are usually worn out in these things, so check them (pull the cover, lockpin, and C clips out to get them loose) where they ride in the wheel bearings...before buying the rear-end! The 55-57 Chevy car rear-end is almost a bolt in, the perches need to be relocated to the top of the housing though. It has the 4.75" bolt pattern, and ratios are usually 3.55-3.73, but sometimes you'll find a 3.36. The 78-88 mid size GM cars use a 7.5" 10 bolt, which is about 58/5" wide. This rear-end would work well in an early (older than 47) truck, but it is quite light duty. Ratios are usually 2.29-3.23, which means you want some torque in the engine to pull it...but rpm will be low. This is a coil spring rear-end, with all the mounting brackets that need to be cut off. The Ford 8" and 9" rear ends come in a whole bunch of varieties, and only a few are useful in oletrucks. The late 50s full size cars have a nice one, but it's not easy to find brake hardware, drum, etc anymore. The mid 60s midsize cars, such as the Fairlane, have a rear-end that is about the right width, and would be a good candidate...if you can find one. The Maverick/Granada is very narrow, about 56.5", and would not fit anything but a very early truck, or perhaps a tubbed Pro Street truck. The 60s full size Ford car rear ends are usually too wide, but if you find one, measure it and see! Most earlier full size, and all mid size, cars use the 4.5" bolt pattern, while later full size cars use the 5" pattern. The Ford trucks have a big 5 on 5.5" pattern, with a big center that takes some work to redrill to anything Chevy. Ratios range from 2.47 to 4.30, and the axles come in 28 or 31 spline varieties. There is lots of interchange possible with the 9" rear-end, which is why it's so popular...I have one in my 55 Belair, and in my 57 Suburban chassis. Unfortunately, they are getting expensive, especially when you have to shop around for just the right one that will fit. So...if you don't know if a rear-end will fit, or what it came from, get out your tape measure and see for yourself! The most important things are overall width, and wheel bolt pattern...then concern yourself with ratio. I like a 2.75-3.0 ratio for a V-8 powered truck that will spend lots of time on the highway; about 3.2-3.7 for a 6 cylinder or small V-8 for in town and limited highway use, and the stock 3.9-4.56 ratio is great if you have to use your truck to haul lotsa weight, and you don't have much engine...just don't plan on going much faster than 55!
see
http://www.chevytrucks.org/tech/

P:\Chevrolet\DRIVE LINE\Chevy VIN, Trim Tag and Drivetrain Information & Decoding.htm
welcome aboard.

Going with the electronic ignition. Going with the 16" tires and after much dialing I've chased down a guy fairly close (100m) who is willing to do the rear end swap for me. I'm meeting with him over the next couple of weeks to let him have a look at what I've got and determine what he can do for me.
Following up on the 4bbl, I've seen a couple of suggestions. Holley 4160, Edelbrock 500 and a Holley 390. If I'm looking at a Clifford 4bbl intake... is the Holley 4160 overkill for the 235?

I'm also thinking which would afford the best fuel economy. I'm not racing anything except my heart whenever I turn that key!

Hy deanomartini, I think a 4160 would be overkill for a 235, I think the Holley 390 would give you the best mileage, of the carbs you've mentioned, good luck with your mods

Hi deanomartini,

First of all, welcome to the stovebolt!

Here's a suggestion. Why not change the gears in the rear, PATRICKS has the sets and they are cheap enough. You could also use a manual transmission swap (assuming you want to keep the manual trans.) to a three speed overdrive Chevy trans from the 50's. They are available and reasonably priced.

Just an idea and my 2 cents worth.

Again welcome and good luck with your truck.

Dave

I'd thought about swapping the gears and have sent an e off to PATRICKS for further information.

When you say a three speed OD Chevy trans do you mean the POWERGLIDE 3.55 tranny from a 50 -54 chevy car?
I've read the tech articles on the T-5 swap and am clear that I lack the skill and fortitude to pursue that angle.

I've got a line on the Holley 390 and am waiting for it to arrive, before I go off ordering an intake manifold.

i am in a similiar situation w/ a 46 1/2 ton and a dead 216 '50 sedan motor. the 235 swaps out all they way until 62 i believe. from the guys at patricks i was told that an early 60's saginaw 4 speed is a direct bolt in and thay have a torque tube conversion piece to swap out the sag tail and keep your torque tube in line. i was also told that patricks has a 3:55 swap for the original rear.
if the 235 i am looking at works out i am going to have some decent rebuildable 216 top end parts and other stuff. if needed let me know

Boy it's a good thing I work the night shift. I've had more time to chase down some earlier carb threads and here's what I think I'm going to go with.

• Holley 390cfm or a Holley Economaster 450cfm

• 235 cam or custom cam from Clay Smith.

• Hunt down a 3 speed OD (sorry about the powerglide confusion) from Gear Vendors or go with "bigedpa" and the Saginaw 4 spd. (though I haven't looked up the gear ratio yet) and Looks like I've got to sit down with a tranny specialist in town to see what he can offer up

• Swap out the rear gears with Patricks 3.55

I'm not too worried about accelerator linkages yet, more about gearshift postion, and any torque tube conversion I may be looking at.

Hy deanomartini, just to clarify a powerglide is a two speed automatic transmission which is direct in high gear, hope that helps.

Just spotted this on our local craigslist: Is this a serious candidate?

Disk Brake rear-end , has same width as the 1947-1955 Chevy trucks. Comes from a 1985 Lincoln with a V8, benefit of disk brakes. Ratio 3:08, posi not known, not 9"

Rear gear is a little steep I think but If I kept the original transmission would the gear ratio be OK. Not known if it is a 5-6 bolt

http://www.angelfire.com/ok5/50gmc/discbrakerearend.html

a company called air ride technologies in indiana makes a kit to install that rearend. it is supposed to be very good almost bolt in with the kit except for the axel perches. i wanted to do it but couldn't find the proper rearend around here and gave up. ron i saw the install done in classic truck mag. about ten yeras ago. ron

Thanks WE b OLD.
I'm giving it a look over this weekend and measure to make sure all is well.
But with the 3.08 gears and keeping my original transmission, am I finally going to be able to use 1st gear?

I've got a line on a Holley#6299 - 390cfm as well. Good or Bad choice? 1-10

a liitle more on my earlier post. if you go the saginaw route you want to look for a "no grove" or "2 grove" shafted tranny. the input shaft (clutch shaft) will be splined and have some or no grooves on it. talking w/ the people @ patricks the 2 groove is the best to install b/c it has the best gear ratios for our engines and rears be it orig or esp the 3:55

give them a call great people and a ton of info.

If your truck is Canadian then the bolt circle on your ring gear is 3/16" different from an American one. Patrick will suggest you buy an American carrier but it is possible to modify yours to work.

Apart from being a 3 groove shaft, is this the saginaw you're talking about? It sounds like the way to go? Do you know if the floor shifter position has to be modified with this tranny?
The truck is a base model from Flint. Nothing

http://cgi.ebay.com/ebaymotors/GM-S...7071QQcmdZViewItem?hash=item330210637071

Got the WISH catalogue from Patricks today. ENUFF SAID!
Looks like they've got everything I need to do the swap over, just need a pocketful of cash to pull it off.

Any newbies following this thread... I suggest (highly recommend) you email Patricks for a catalogue.