New EEC, new wire harness, new motor mounts, new tranny, new rear end, new radiator, need a hood with a cowl unless you get motor mounts that lower the engine.
Basically you have to gut all the mechanical parts and replace them plus the engine computer. The v6 tranny and rear end could hold up, but you'd have to baby the heck out of it and have an older stock 351.
Get a G-Force T-5 and an 8.8 for DTS. You'll be set.