Your mileage may vary, but my parts costs for the impending 5-speed conversion are: transmission $ 200 shortened and balanced driveshaft $ 350 T/O bearing, slave cylinder, altered shifter platform and mounts, other associated hardware $250 I did shop carefully to get good stuff cheap. And I suppose the transmission (with 80K miles, from a trusted source) could go bad prematurely. But even with a couple extra hours of labor I will bring this in cheaper than a rebuilt 4-speed ($1100 price tag, not including installation). Plus, it will have the aforementioned extra gear.