since the 351c was available in the 70 mustangs, and since the 69 and 70 stangs were virtually identical, the swap is an easy one. you should be able to use the 3spd in the car with the right bellhousing. i would swap to an 8" rear end at least though. you also need the V8 chassis and engine mounts as well as the exhaust system, rad, linkage bits, etc. etc. etc.