Well from what ive heard from a few other people, If i went with the O.S. motor i would only have to mod the trottle linkage. The motor should mount up to the old holes on the chasis and everything. Its also proclaimed itself as the fastest small block .18 motor to date so hopefully it will be all the motor i need. I think this is the motor im going to buy, Now i just have to find the cheapest place to buy it from. lol