rearend gearing options

Many second gens came with 3.08 rear gears. My car, a 75 LT, came with a 350 4 barrel, 4 speed, and 3.08 open rear. With 255/60 R15 rear tires, it cruises on the highway at about 2400 rpm at 60 mph.

 

upgrade to an overdrive trans, it's much more worthwhile...

 

is 3.08 vs 3.42 really worth the hastle & expense?

doesn't seem like much of a difference

I went from 3.50 gears to 4.11s in a 79 F150 (36" Buckshot mudders...those were the days) and I almost couldn't tell a difference at all

 

3.08s with a low first gear 4 speed would make sense, but with an auto I'd just do a 700R

 

You could do a 200 4R without having to modify the cross member, drive shaft or anyting. If you do the rear end then I would recommend finding a 3.08 rear end and swap the whole thing. Then you can store your original rear end for when you want to put it back to all original.

 

2.73s use the same carrier as 3.08s and 3.42s if you can find a set. Lots of Pontiac guys dump their 2.41/2.56 carriers and gears too. Problem with those gears and a normal first gear is getting moving. My 79 Camaro had the 78 TAs 2.56 in it before we swapped in 3.73s. I swear it could idle at 25 mph in first!

My 81 has 3.08s and still seems to be screaming at 70, especially when you are used to a daily driver with an OD tranny.

 

You can always run a taller tire first.I have 3:42 gears in my 1979 Z-28 Camaro I have run it as turbo 350 automatic ,and a 4 speed car both with P235 60/15 it cruised around 23-2500 rpm at 60. So try going to a P275 60/15 of which is a taller tire.And try that because its lot easier on both the pocket book and your back.And if you don`t like it. Its always easier to change it back.