What engine to use

I just got a 68 dart 2dr 6cly. from cali and it is a pretty clean body.Cleaner then I am used to on the east coast. I want to change the engine.I want some input. Sould I go 340 w2,3rd gen hemi, hemi, r5 p7 engine or p7 head with xr block? I would like to pro tour the car.
Author: admin