Question: changing differentrel

[Pipeliner]

What gears are in my 1980? I want to put a 140mph speedometer in my car and want to be able to get close to that mark. also what speedo gear is in the th350 tranny. Need some help.

 

[Vettehead Mikey]

Your car was built with a 3.07:1 gear ratio diff. Changing ratio won't help much with top speed.

 

[Pipeliner]

Your car was built with a 3.07:1 gear ratio diff. Changing ratio won't help much with top speed.

What would I need to do to get the top end I want with out red lining?

 

[VETTETECH]

An overdrive transmission may help...:eyerole

 

[Vettehead Mikey]

An overdrive transmission may help...:eyerole

And lots more horsepower.

 

[Pipeliner]

And lots more horsepower.

I have got a 383 stroker just waiting to go in but right now work takes my time.

 

[VETTETECH]

I have got a 383 stroker just waiting to go in but right now work takes my time.

I recommend that you do the math..To do 140 mph, you don't need to tach the engine into destruction..The 383 will make gobs of torque so you can keep the rear diff. ratios below 3:55..A 6 speed with a double overdrive may get you there..There are some online simulators that will give you an idea what the engine will need to tach at 140mph..Keep it under 7000 if possable

Joe

 

[Tom Bryant]

Click on Tech Center in the top header of this page for a drop down menu. At the bottom of the drop down you will find Toolbox Calculators.

Tom