Wow, an FMX behind a Cleveland. Is it a 2bbl or 4bbl? Well the FMX isn't a performance transmission. I would find a suitable C-6 for a smallblock and rebuild it with a large tranny cooler. On the manual side, you'll need these parts: Clutch/ brake pedals, clutch linkages, bell housing, clutch, pressure plate, flywheel, flywheel bolts, throwout bearing, oh and a manual trans with shift linkage if applicable. The Tremecs are nice however not as indestructable as they seem. After seeing my brother and nephew having to go through their 500's I wasn't that impressed. Of course they're pushing close to that in hp. It all boils down to how you want to drive it. Me...I'd go for the manual any day.