I'd go with the AOD. It makes the V8 a little more suttle and manageable. If you had the AOD and needed to stop on a steep grade it will just hold you there, with that kind of power and a clutch it would make it a lot harder to get going again without slipping. The .67 to 1 overdrive is great for cruising also. The engine and trans move the tcase back about 5.5" and the adapter cost about $525.00.