Best rear end and tranny for stock 235

[1953]

Ok i want to know what is the best rear end and tranny for stock 235 engine i want good take of speed and highway, i see so much controversy on the best rear ratio, what is the best choice of rear end that has disc brakes and that can be a axle over spring on a 3600, im converting to axle over rear with frame notchs and going to do a front end swap also, basically update everything while i keep the 235 engine i have,

[mongocanfly]

A zr2 rearend comes with 3.73 gears, locking diff and disc brakes and is 3" wider than a standard s10..its a good choice but may be hard to find..8.8 explorer rearend is also a popular choice..

[1953]

What is the gear ratio on a standard s10? And how does it perform with a 235

[mongocanfly]

Could be anything from 3.08 to 4.56...would have to check rpo code to know..
GU4=3.08* GU5=3.23* GU6=3.42* GT4=3.73* GT5=4.10* HC4=4.56* ....
G80 is locking differential

[mr48chev]

copied and pasted off an S-10 board

Most of us idiots use a 4x4 one. Those are 58" wide.

Those are:
3.42 axle ratio (opt GU6)
3.73 ratio (opt GT4)
4.11 ratio (opt H04)
3.08 ratio (opt GU4)

As far as I know, the 2wd ones had the same ratio spread, too.

Off that same board and I am not sure how accurate it is as the numbers don't match some other axle pages

2wd 54.5"
4wd 59"
ZR2 63"

Two wheel drive is too narrow for your truck as you would have to put mini tubs in.
4 wheel drive comes real close to stock. Back spacing may be an issue with some wheels though.

5 lug Dodge Dakota would give you open drive with a Mopar/Ford 5 on 4-1/2 bolt pattern with a choice of gear ratios but you want a rear out of a V8 truck as the 4 cylinder rear axles are wimpy. No disk that way though.

I put a 56 three speed and rear end in a 53 for friends of mine and they drove it all over the country after it was done but didn't drive very fast as they had a bit canopy/camper on it. It really didn't gain any road speed that way. We used engine, trans and rear axle out of the 56.

First I would figure out what lug bolt pattern I wanted to go with on the front and go from there.

[Jemezcrusher]

Have a 8.8 in my 50. S10 tranny with OD. 5th gear is .72 making my 3.73 about a 265

[joedoh]

keep in mind a 235 wasnt made for sustained high rpm operation, and doesnt have a ton of torque to be used in a low rpm high road speed application. try to stay around 2000-2500 rpm for continuous operation.

a 3.73 with normal sized tires (lets say, a 235/75/15) with a 235 and stock trans turning at 2000 rpm will net 46mph. 2500 rpm (probably ok for short stretches) would get 57mph. you will need more gear. higher rpm for a longer time will probably just puke oil out the breather.

overdrive is one way, there are a couple how-tos on this site for using a WC T5 trans from an S10 or camaro, just adding the .76 overdrive will make 2000 rpm a 60mph and 2500 rpm 75mph. you will probably run out of torque to overcome aerodynamics before that.

with the stock trans and a 3.07 gear, 2000 rpm will be ~75 mph. a 3.07 will likely make 1st gear of the stock trans, normally a granny stump puller, an actual useful gear. your limitation will probably be the torque of the stock engine, I think.

your stock 3600 rear gear is probably a 5.16. top speed right now at redline is probably 45 mph. they do not make new gear sets for the eaton rear, I have heard rumors of a 3.55 but never found anyone who has bought one.

[svr]

Tom Langdons web site has a page that grades your trans and rear gears for the 235, if i remember correct a T5 with .72 OD and a 3.73 rear was right up there as being very good. He has other suggestions.

[1953]

Well cracked open the rear end and o have 32 ring teeth and 18 pinion teeth did the divide thing and got 1.7777778