I know this question has been asked numerous times, but here is a slightly different twist. I have a 396 with 4L60E and 3.73 gears. 60 fts are in the 1.43-1.47 range now with 11.30-11.39 @ 119 in the 1/4 on motor. I also have a 150 shot which picks mph up to 130+/-. I shift at 6700. With the 4L60E, will first be too short with 4.10's? Will I run out of gear in the 1/4? I run 26" slicks & street tires. I have plugged the numbers into a rpm/mph calculator and it looks like it would work, but i'm asking for someone that has seen real world results. I know street traction will suffer, but with this motor it's a joke already. I guess what i'm getting at is in your opinion will 4.10's make me faster?

 

I'd go with a 12-bolt, 4.10's, and a 28" slick. I know those low 1.4 60fts. are putting some serious strain on that 10-bolt. IMO I'd stick with the 3.73's since you will be running dope. Let me know when you will be going to the track. You should see low 10's on the dope. All with a 4L60E and a 10-bolt.

 

Anyone else have a suggestion?

 

sorry, double post

 

what rabbi/priest/monk did you have bless your 12 bolt? I'm afraid of blowing mine with my nearly stock car.

anyway, sorry i dont know, ttt for ya

 

Autos are much easier on rear, though 1.4 60s put a lot of stress on the rear any way you cut it. I think 4.10s will be to much gear. The thing that the gear ratio to speed calculators don't take into effect is converter slippage, however the slicks will expand when you get going faster.

 

Thanks for the replies guys.....is there no one out there that has 4.10's in a 4L60E car?

 

Please come and bless my 10 bolt all might one


I know you have already heard this, but i have seen running great times and mph with 373's. I really haven't seen anyone running 4.10's. Maybe there is a reason.

Good luck

 

I am running 4.10's on a heads and cam 350 LT1 Impala. I run 26/10/15 Mickey Thompson slicks and with a 26 inch tire the 4.10's will turn into aprox 4.30's. I have the 8.5 30 spine 10 bolt so I am not a worried about my rearend exploding as you should be. Do I think 4.10's will benefit you? Yes. Will the rearend stay together? Well I think you know the answer to that. I have read though that if you run juice a taller gear is more benefial than a shorter gear due to winding out so fast. With juice and 4.10's in a A4 car I can bet you will hit lock up before the end of the 1/4 mile. Also if you do any street driving 4.10's are real fun. I run 255/50/17's and at 75 mph I turn 3000 rpm's. Car loves fuel. If you are running 275/40/17's or 16's the rpms will be even higher. I will quit babbling. Good Luck!
HVY SS