Rear Gears.....?

[transamguy79]

i have a 1979 trans am with performance cam, roller rockers, edelbrock intake, full exhaust, 2400 stall converter. and im having trouble deciding what rear end i want to go with. it still has the stock 2.73 rear gears in it now, and i wanted to know what rear end gears i should go with. im lookin at 3.73, 3.90 and a 4.10 rear gear setup but i keep hearing good and bad things about each. so could you give me some tips or advice on which one i should get.

[Whoaru99]

Originally Posted by transamguy79

i have a 1979 trans am with performance cam, roller rockers, edelbrock intake, full exhaust, 2400 stall converter. and im having trouble deciding what rear end i want to go with. it still has the stock 2.73 rear gears in it now, and i wanted to know what rear end gears i should go with. im lookin at 3.73, 3.90 and a 4.10 rear gear setup but i keep hearing good and bad things about each. so could you give me some tips or advice on which one i should get.

Depends on your ultimate goal; 1/8 mile, 1/4 mile, top end, "average", etc.

Besides knowing the general purpose of the car, engine size, cam specs, heads, and intake style must be known to properly choose the cam. By full exhaust, I assume headers and back? Did you upgrade the valve springs too?

Your best bet is to phone some of the cam vendors and ask for a recommendation - they will need to know all this stuff.

[Earlsfat]

Depending on what you're going to pay for the rear... I'd replace the trans with a richmond 5 speed, 2.73's will work just fine, and the gearing in the trans will get you the low end grunt you're looking for.

I think they run around 1800... local speed shop quoted me 950 to have new ring and pinion installed --- another 850 and you've got a brand new trans and decent highway speeds to boot. 4.10's and 3.73's will kill your top end unless you have an overdrive trans.

EDIT: 2400 stall converter = auto trans... have overdrive? if it's .62 or lower go with 4.10's... you won't be disappointed.)

[Savage Messiah]

4.10s... well unless its got no OD and sees a lot of highway time, then use some tiny 3.73s or so

[Morley]

3.42 would be a good all around rear gear for a 3 speed auto car. You'd be running about 2600 RPM at 60 MPH and you'd still be able to spin the tires on launch.

[Savage Messiah]

3.42s... I don't miss em. But they are a good middle ground.