360 or 318 magnum

If they're both truck engines and you plan on converting from the fuel injection sysytem to carburation I'd go with the 360/5.9. The Mopar performance crates where the same 5.9 magnum truck engine with an M1 intake and depending on the date, started at 300 horsepower and by the end of the production upgrades were in the 380 horsepower range and torquey as all get out too.