I’m halfway done on a 69 Charger but the unit is in. I had to drop it more than the .100 they said to drop the crossmember. Otherwise I would have had to clearance the whole tunnel for the unit instead of just the bolts at the rear section. They give you a template where it needs to clear. I ended up using smaller 3/8 bolts instead of the factory ones so it dropped it over 3/8”. 71 had 3/8” bolts to begin with but you may be able to drop the motor mount some. This one is close. I hope it does not hit on bumps.