4 speed install on 68 Dart, 440 6 pack

Cool car!
I have a few questions:
What headers are you running?
How much of a pain was it to get the bell housing centered to the transmission?
What is the rear end and the gear ratio?
Thanks,
Tom.
Headers - Schumacher conversion headers. Had to do some minor fab ing to reroute the drivers collector to clear the clutch z bar.
Bell housing - It comes with two different size centering rings, I think mine took the smaller one. I took the input collar to my friends machine shop and he polished the down OD of the collar so it fit cleanly in the adapter ring.
Rear - 3.91 with sure grip.

Let me know if you need any other info.