I have a 1970 Chevelle SS 454(540 hp, 580tq) with a TH400 street trans, 2200 stall and 4.10 posi gears in the 12 bolt rear. My question is what would be a good all around gear to enjoy the car and not be reving all the time? Thanks, Leo

3.31's if you can find them, if not 3.42's.

Dave

i have 3.73s and drive it around town and to work with ease. and can still stomp on it and push you back in the seat.

I had 3.31's and just went to 3.55's. Not much difference but I like it better and so does my combo.

Both of our cars are 4.10 geared and the revs never hurt them. What the revs do is kill gas mileage and puts a pain in your wallet. That's about all that gets hurt.

Both of our cars are 4.10 geared and the revs never hurt them. What the revs do is kill gas mileage and puts a pain in your wallet. That's about all that gets hurt.
Plus your ears if the exhaust is loud enough. Go with 3.73 for best all around service.

With that kind of torque and converter, you might want highway gears. Seriously, with that kind of power, how much of it goes to the ground on the street? If you go 3.31, 3.07, or even 2.73, you may not spin them anymore from a roll, but what will happen is that you will go forward -- much faster. Spinning tires and fishtailing is okay for trying to impress people at the bus stop, but for speed and performance it makes sense to gear your car so that all that power isn't wasted by unnecessarily leaving stripes on the pavement.

I have a much more mild engine with 2.73's in the back and it will still roast them at will at a stop light. When I'm moving and punch it, it does the surprisingly efficient thing of moving ahead.

Also, if you go down numerically to highway gears, make sure that the downshift is properly hooked up. The downshift can be real annoying if you have huge torque and steep gears, but with cruising gears, it's a perfect compliment. It will get you out of the hole when already rolling.

Plus, you'd be able to go on those long summer road trips without killing your ears and wallet.

3.08s

The '70 has 3.31's. I don't think I'd go much higher than that. I want to put 3.73's in my car.

He has auto trans with stall that may have a sight amount of slippage over a man trans setup .

So for his setup with slight slippage fro auto trans and additional stall over stock id get a used or nos set of 3.31's from ebay etc .

But if it were a manual trans setup i'd get new 3.42's which sould be same approx cruise rpm as 3.31's with an auto trans & additonal stall setup.

I have bought 2 used sets of 3.31's off ebay with issues,they were installed my car and my friends car and both sets worked out ok .

But in my case the shop that installed the 3.31's for me didnt use any loctite on the pinion nut and it loosened up 7 they also didn't use any silicone sealer on the pinion shaft spline to stop gear lube from weeping out & leaking.

I had to reseal the pinion shaft and re-trq the pinion nut using loctite myself,the shop that installed my used 3.31's said rear end yoke was bad causing loose nut and leaing grealube,yeh right!!!.

And this was done at a local shop with good rep that has over 35yrs in rear dif/trans rbld expeirence with same experieced people still doing the work.

After i fixed it theres been no more loose pinion nut and no more gearlube leaking from rear pionon 2 yrs after i fixed it,so much for it being a bad rear yoke causing gearlube leak & loose pinion nut like the shop said was the case.

Too dang bad i didnt live close enough to have BIGEARHEAD/Freddie do the ring & pinion swap for me because he knows what the heck he's doing & it would have been done right the 1st time with no issues.

Scott