[eatonde]

Hey guys, I have a problem..... I have been trying to find the answer to this question for a LONG time now... I THINK I have 308 gears in my car now, but i don't no how to tell for sure. I know it is stock gearing in a 82' cutlass supreme. I know that with the old SBC 350 that was in it was bored 80 over from jasper engines, It had a 750 holley DP and a perf rpm intake, TH350, and it would burn the tires off the car. In a straight line both tires would spin for about 5-10 feet then after the got going faster one would stop spinning and the other would continue. prolly a 30 ft black mark

Now I have a 355 in it with a TH400, same gear (getting changed)..... My 355 has a lunati bracket master II 300 cam in it. I just wanna give you some I dea of the current gearing..... Even with the big cam stock stall, the thing will still roast the tires for about 15 ft.... Even going along at 10MPH and punching it (NO STALL YET) (STOCK) It will still do a decent burn out.

I need to know what gear I have so I know what I can buy to replace it... I know Its a 7.5" diff, but I don't wanna cut into it till I have a new one to put in, but I can't order a new one till I know what I need.... . Please help If you can. My car was not the grandma version of the cutlass, It cam factory with a 307, TH350, sunroof, spoiler, ect....

I'm almost to the point that I'm thinkin of puttin a 4 or 5 speed in it to have better drivability with the big cam. The stall I have is a 3300-3500 rpm Dacco competition converter, but I am just wundering how much around town drivability I'll sacrifice with that much stall. My buddy has a B&M 2500 in his truck and you can't even tell its not stock... How bad is mine gonna be???? If I stick with this stall and the TH400????

[sunsetdart]

You can count on higher trans temps when running a hi stall speed. I have a 3300 in mine and on a hot day the trans gauge will see 200-220 and I have an external cooler.

[eatonde]

I am using the AC coil for a tranny cooler. I have a 14" electric fan in the front, pushing, and a clutch fan on the motor pulling. That thing holds almost 2 gallons of extra fluid so I think It'll stay pretty cool. Mabey too cool in the winter.

[ScoTFrenzel]

Originally Posted by eatonde

Hey guys, I have a problem.....

I know it is stock gearing in a 82' cutlass supreme.

Many of them had 2.26 gears with the 3 spd auto trans.

Jack up one rear wheel. Put the trans in neutral. If the one rear wheel will turn, you do not have a posi. Then count the number of driveshaft turns for TWO turns of the one rear wheel. That is the gear you have.

If the one rear wheel will not turn, you have a posi.
Jack up both rear wheels and count the amount of drive shaft turns for one revolution of the rear wheels (turning simultaneously because they are posi). That is your gear ratio.