4L60e - what rear end gear to go with?
 

I have a 95 impala ss with a 4L60e transmission in it. It has the stock 3.08 gear in it. Wanting to upgrade the gear, but not sure what gear I want to go with. The car will mostly be a weekend cruiser with occasional track time. I had a 350 trans with 373 gear that ran 3000 rpm at 60 mph, didnt like the motor reving that long on long stretches. Any suggestions on a good all around gear, with good take off and good street manners?

3.42 would be middle of the road between 3.08 & 3.73. but you have to remember the 4l60 trans is overdrive & th350 is not, you wont be turning 3000 @ 60 mph with the 4l60 trans.

Yea I know that its an overdrive so the rpms would be less with a gear compared to my 350 and 373. I was thinking of 342 or 373 myself, also running the stock 17 inch rims with a 26.5 inch diameter tire.

in theory just adding the overdrive ratio of .70 you should be turning 2100 rpm. Thats without a lock up convertor clutch. if you add lock up i'll drop it about another 200-300 rpm, maybe a little more. alot of the f-body guys go with 3.73's. get down below 1500 your just going to be into the convertor stall so much it'll nuke it.

IMO...I would leave the 3.73's in and try it. If they are not what you like then change them.

TS1955

i WOULD AGREE

Using one of they many rear gear calculators available on the net, at 2850 rpm, with a 26.5 tire diameter, with a 3.42 gear it will cruise at 65 mph. So, ive decided to go with a 3.42 or a 3.55. Any recomendations on what gear would be better? I am planning on a 2800 stall converter and a .525/.525 LT4 hot cam conversion.