I am building a 550hp 383 which will find its way into a 3rd Gen. The car will be a street/strip car, and I was after recommendations of what auto transmission and diff to use. I am planning on running 4.11 or 4.44 gears, so I would prefer a trans with overdrive. Both will need to handle full launches with slicks at the strip.

Can a T700 be built to take that sort of punishment? If not, what other overdrive trans will take it? Are my only options for a diff a 9" or Dana 60?

 

a built 700r4 would handle that power. Also a 12 bolt, 9" or a S60 will be fine.

 

For less than 600 HP I would use a Moser 12 bolt. It's lighter, cheaper and easier to turn than a 9 inch, and more than strong enough for 600 + HP. I would use a 33 spline Eaton Posi with 33 spline axles and 9 inch Ford axle bearings to eliminate the c clips.

 

I have a built 700r4 with a 3200 stall
My best et is 11.0 @ 125.
I have 4.11 gears.
The trans is now starting to show symptoms of weakness and it is starting to slip when I shift from 2-3, although I have been racing this trans now for 3 seasons

 

I have the original rear housing with an eaton posi, moser axels,4:10's rear cover and we are running a 500 (to the ground) 383 launch at 2500 WITH THE STOCK 5 speed! Runs 12.5 all day. Plus we road race the car. It was the second fastest at Taladaga Grand Prix lat time out!The stock trans has a bad bearing but it took 5 years to do it

 

My original thoughts have been altered slightly from street registered strip car, to street car which occasionally gets used for the strip - seeing as the racing facilities around here are not exactly world class.

So drop the power to around 450, which is plenty for the street, and go to a manual gearbox - probably a TKO600, and 12-bolt diff, should be lots of fun!

 

No fun.. 550+ hp for the street, TKO600.

I'll probably go TKO when my TH350 blows up.

-- Joe