What gears and convertor stall ?

Here's what I have

545 @ 11/1 compression
260/268@.050 296/304 .726/.726 108 roller cam
Blue thunder heads no porting with CJ ports
1050 dominator and Victor manifold
This motor dynos 600 tq at 3100 rpm with a max of 650 and stays at 600 till 6000 rpm
hp is 650 max
3600 pound Ranchero with a C6 and stock suspension.
28 x 10 slick is the largest tire I can run right now.

What rear end gears and stall do start with?

3.70 to 4.11 depending on if it will be Street & Strip,mostly Street or mostly Strip.My cousin has used 3.89 gears in his 73 Mustang at 3,600 lbs. with a 466 it ran 10.50's at the track with the size tire you mentioned.

Later Mark.

Sure thought I would of gotten more of a response.

Sorry you haven't gotten more responses,i would also use a 3,500 to 4,000 rpm Torque Converter if it's making 600 ft.lb. at 3,100 rpm IMO.

Later Mark.

Mark thank you for the input.

Sure thought I would of gotten more of a response.
street or strip?
600 hp at what rpm?

Using 600 hp at 6000 rpm and a 3000 rpm converter, I get 4.30's
Using 600 hp at 6000 rpm and a 3500 rpm converter, I get 4.00's

street or strip?
600 hp at what rpm?

Using 600 hp at 6000 rpm and a 3000 rpm converter, I get 4.30's
Using 600 hp at 6000 rpm and a 3500 rpm converter, I get 4.00's

600hp at 4700 rpm and 657hp at 6000 rpm

600tq at 3200 rpm and 670tq at 4600 rpm

600hp at 4700 rpm and 657hp at 6000 rpm

600tq at 3200 rpm and 670tq at 4600 rpm
Same question, street or strip?
If it were me based on somewhat limited street use, with a bias towards strip, I would go for 3000 converter and 4.11's. The harder you want to run it the more things change. Your version of streetability may obviously vary.
You've got a lot of low end torque to control. You are definitely going to have to work on the suspension, stock aint going to cut it. If you don't work on the suspension, spin, spin, spin, even with slicks, in my opinion.
There are so many things to take into consideration that this is just a guess, for instance I guessed at 175 lbs for driver, there's lots more, it's a lot easier to get the gear ratio right after it's ran a few times, but for starters, and guessing on a lot of things, 4.11's, 3.89 if you want to be more conservative.

Very limited street and the car is coil spring rear suspension.

I have southside lower link bars and a roll control bar installed.

I am finishing the roll cage installation now, so the frame will be stiff.

With the stock style rear suspenion I would stay around 3500 range on the stall and 3.89 or 4.11 gears. I use 28x10.5 m/t et drags and 4.10 gears and go through traps at 6000 rpms, you are making a considerable amount more power than me so the 3.89's may be better suited to you.


I read in a tuning book that "if you can achieve traction a vehicle will go the quickest with the stall speed matched to the peak of your torque curve. With limited tire rules this is not always ideal as traction becomes a real issue."