Just 'man up' and rebuild your FMX. Nothing to it, really. I wouldn't put in an untried or unknown C-6 (or any other trans for that matter) without going through it first. Nothing worse than going through all of that headache (cutting driveshaft, different trans crossmember, cooler lines, linkage, etc) only to have the 'new' trans go to crap after a week. Case in point - I took a running AOD out of my '89 Crown Vic, and put it out back behind the barn... Two years later, a buddy needed a AOD for his car, so he's hot to drop it in. Well, those pesky wasps built a nest inside the cooler fitting, plugging it with mud. Good thing they checked! The then took the trans apart to gauge overall condition (it still had the 'cherry' in the pan, too - at 205k miles!!!). The O/d band was almost toast. They went ahead and rebuilt the trans, and now all is right with the world. It'll probably last another 205k miles!