Posting this question for a friend who is in the process of reviving a '72 Challenger Rally. He is going back with a 360 crate motor (1974). The question is are these 360's internally or externally balanced? What balancer and flexplate will work (727 TF)? He has the balancer and flexplate off the 340 that came out of it many years ago. Thanks in advance for your help.
Jack