well, personally im running the 80 series and love it. maybe you just need a V8 to pull it off
lol jk. as far as swapping in a V8, you need new motor mounts, new radiator, new hoses, new accessory mounts, belts, and the accesories themselves, new AC lines, (if you run AC) new heater core lines, new wiring harness, new fuel lines, new intake and air box, new ECM, new PROM, and probly a few other things im forgetting about.