my 416 build is gonna be ready within the next few weeks. i have a 727 stall 3 speed tranny (shift kit) with a stall of 3500 rpm. and the back end is 3.91 richmond gearing. that was pretty much just enough when the engine was a 340 0.040 oversized. so im thinkin that now with more power and torque im gonna be shifting sooner. am i gonna have to change the gearing to 3.73?

thanks for ur input!

I think the 3.91's will be fine.

Your shift points may go higher rather than lower with the new set up.You will have to play around until you find the sweet spot again.

Well tire size makes a huge difference what will you be running??
6500 with 26 inch tire will be 118 out the end
6500 with 28 inch tire will be 127 out the end
6500 with 32 inch tire will be 145 out the end

am i gonna want to run it to 6500 rpm? i was thinking 6000 to be safe...

My '70 duster with the 416 in it ran 11.0's at 120 mph with a 3.91 gear...i think you'll be fine

Spin it 'till it stops making power...