IroczFan

I have a 1986 IROC I bought It bone stock almost with a 305TPI headers and a 700r4 273 limit slip rear end, it ran a 15.14 @91mph for best time, scince then I have got the trans rebuilt corvette servos transgo shift kit and 2400 stall the 305 was pulled out and I have a 383 Stroker 10.8 to 1 compression forged pistons rods 906 Vortec heads elgin Cam 484/484 lift RPM air gap intake holley 750 DP carb still has the stock rear end.. wondering what you guys think I will run with the stock rear end and afterwards when I put in a locker and 373s

five7kid

iTrader: (14)

Assuming you have traction and a decent tune, you should be in the mid- to high-12s with the 2.73s. With 3.73s and traction, probably low-12s, maybe high-11s. I'd want more stall, though, to insure running those numbers.

five7kid

iTrader: (14)

BTW, when you put in the 3.73 gears and locker, get 28 spline axles.

IroczFan

will thouse work with my rear end scince its 26 now?


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GreggymacZ28

You would have to just order a 28 spline locker instead of a 26(if you bought the 28 spline axles). Also, I would think that even with a locker and 3.73 gear my prediction would be around 12.6. I agree with five7kid that with a bigger stall you would be a lot better off.

five7kid

iTrader: (14)

Yes, like Greggy said. You can "even" go up from 7-1/2" gears to 7-5/8" gears.

I did all this in my '83 rear, originally with open 2.73 gears and 26 spline axles.

You may want to consider a Detroit Truetrac rather than a run-of-the-mill posi like Eaton. I just discovered broken off posi disk tabs in mine. It'll get a Truetrac next week.

IroczFan

I deffinetly wont cheap out on the rear end, no point in spending money on cheap parts


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paul_huryk

Unfortunately, expensive parts do not necessarily equate to longevity when you are talking 7.5" GM rear ends. I've seen dozens of ring gear failures and even a few bearing problems (I spun the pinion race once myself) that honestly relegate these rears to the "want a stock rear for originality" category. I've never seen a broken axle in person, although have seen a few c-clips fail. I nuked 2 7.5" rears driving normally with a 300hp 350, yours will be more powerful and have more TQ.

My suggestion is to find a 3.23, 3.42, or 3.73 factory 10 bolt for the 3rd gens and swap it in - no reason to spend $1k to break it the same as a factory stock rear IMO.

IroczFan

car ran a 13.40 @ 105 un tuned and trans shifting to early Im sure to see 12s after the tunning and issues are worked out

IroczFan

13.11 @ 106mph now has Detroit locker 342gears LCA with relocation brackets easy 2.0 lauches other wise it wheel hops