EFI Magnum engine/trans in old A-body (65 Barracuda).

‘been thinking of replacing my daily driver Camaro with a an old Mopar with a 1990’s 318 to benefit from the EFI and other Magnum design features.

Question is, what are the high-cost/problem areas?

My plan would be to buy a complete engine/trans off a Magnum truck from the junk yard and drop them into a ’65 Barracuda or similar model.

My four main worries are: headers, transmission clearance, driveshaft, and ‘correct’ pressure fuel pump from tank. What other areas could give me problems?