t-56

New driveshaft, reposition transmission cross member, and you will need a new clutch. It will have a different splined input shaft than your 10 spline. TKO500 and 600's have a 26 spline I believe so most likely the T-56 will as well. Check it out for sure before you buy the Tranny. Could be a long laundry list of parts to change.
 
I'm going to be buying a T56 conversion kit from D&D Performance. It comes with the transmission, custom crossmember, the bellhousing, and an aluminum driveshaft. There are two options: standard spec and viper spec. The standard spec will accept your stock clutch and the kit costs $1,100 less. The viper spec requires a 26-spline clutch plate.

My understanding is that the T56 from a GM will not wire up to a Ford without some additional custom work.
 
thanks for all your replies everyone. i don't think I'm going to go that route considering all the modification costs. And with all the problems I keep reading about other peoples 3650's, I really don't want another one. I did however, end up finding a brand new t45 for $450.00. Was wondering what I would have to change other than the shifter to make it work? Seems as though the clutch and everything else should work. Anyone know for sure?
 
Really? I know a lot of people still running their stock t45 after 100k miles with no problems. I'm going to keep the mods pretty mild on the car. Just don't want the 1-2 grind or other 3650 problems. Plus rebuilding my 3650 is going to cost like $500-$600 considering it needs a new bellhousing on top of sychros and what not. I know a t-45 sounds like a step back in performance, but it almost sounds more reliable for a mild daily driver. Any other opinions on this?
 
I'd say go for the T-45, since they are plentiful, and cheap. I just hit 75k with mine, and it's still running strong, after some serious beating on. After I did my clutch, pivot ball and fork, and filled her up with synthetic Synchromesh, it is the best shifting transmission I have ever felt.