best gear ratio

[WanaBa442]

Carrier break is at 3.08. That and numerically lower are series II
3.23 and up are series 3.
If you're going that route I'd stay away from an offshore "posi" for less than $200.
Find a Camaro rear with a Torsen unit and gears and bolt it in. Axle spline count is different than your stock 26 spline so you'd need those too.
See how one thing leads to the next and the next and pretty soon you haven't driven it in a few years?

 

[jcelk]

i googled torsen unit to see what it looks like different than the one with springs what kind has springs ? i have read the camaro has 28 spline axles can i use the camaro axles or do i need to buy grand national axles ?

 

[Rt Jam]

Torsen is completely different than clutch. No parts interchange and they operate completely different too.
Changing to Grand National axles is a waste of time. They are only 28 spline and are almost 40 years old. That means 40 years of wear on the bearing surface.

At this point, order new axles and upgrade to 31 or more spline.

 

[spongbob]

Yeah ...342 is the lowest without over drive going to be 3000 rmp in 3rd at 67 mph with 17" 235s witch fill the wheel hole good ....3.26 may be safer it's a change from 2.70 ect

 

[doood]

I might could sell you an 8,000 mile 7.5" 26-spline unit with Eaton clutch posi. It currently has 3.55 gears that are burnt-up and noisy from my abuse and improper break-in. The posi carier was new in 2021. I am in the process of rebuilding this surplus 7.5" with new 3.23 gears, but I might not finish it since I found a better 8.5" rear. If you're within a couple hundred miles of Philadelphia, part or whole could be yours. If you're further out, I could ship you the posi and gear set. Not sure what kind of grip you'd get out of a peg leg with asymmetric air spring.

PM me if interested.

 

[Ernest]

Down the rabbit hole we go.... having to change one thing, turns into another, then another, then another, etc.

From what i've seen online... you can keep your 2series carrier when switching to 3series gears if using an spacer ring, or find 3series gears that are made thicker so the spacer isnt needed.

The best you can do w/o burn'n up the RPM, especially if you see any highway use, go with either 3.08 or 3.23 gears for more pep in your step, or use 3.42 max if in town on the streets only to keep things more than reasonable for that motor.

 

[jcelk]

I;m going to the trans guy next week he knows about rears also .. when i was 18 i had a 1974 dart a smog 318 blew the rear went to the junk yard bought a $ 50 rear out of a mid 1960 s dart bolted right up .it would hooked up and was fast off the line alot of fun to drive guess i got lucky it;s true .a blind squirrel finds a nut sometime

 

[jcelk]

just saw the trans guy he drove it and wants to put in a shift kit to make it firmer .. 2 of his guys are out so maybe in a week or 2 a 323 posi is in its future thanks all for you input

 

[Ernest]

Nothing wrong with a shift kit, but i'd prefer to have one put in when the transmission has just been rebuilt... and the 3.23 sounds like a winner.

Shift kits are great... i had one put in a stock rebuild TH350, dont remember the brand, this was back in the mid 90s, it was programmed for firmer shifts with a 2000rpm stall convertor. I had a 355cid/350hp 9:1cr motor up front along with 4:10 posi in the rear, when taking off firmly from a light, while leaving it in auto mode, when it shifted, it would chirp the tires, then a firm bump after that.

Good Times