I don't mind loud exhaust.

A Dakota Rt has more horsepower than a 1984 318. I don't know much if anything about backpressure. Magna flows site does say 2.5" duals are ok.
The a-body kit comes with turbo mufflers which Im not positive I'll like.
Im sure they have talked about backpressure on powerblock before or one of the car shows. I think Ill do some more research before I spend the cash. I still find it hard to believe there are no exhaust guys on here