I NEED A 4.11 Differential

[anglersoutreach]

Thanks for your replies.

The 4:11 will allow the 391 to run 60mph @ 2100rpm. Considerating the
stock 391 produces maxium torque at 2600-2800 rpm. I will be able to
run 70 mph @ 2450 rpm. A 4:56 may possibly be the better choice of gears.

I plan to change the camshaft, intake manifold, and make several other
modifications to the 391 that will enable it to run at these rpms
efficiently. These improvement will not decrease the dependability of
the 391. I am even considering replacing the Allison mt40 with a 545
to get rid of a lot of rotating weight.

Thanks, Billy