Well you would have the horsepower, but with all that weight you'd be at such a disadvantage! If I was going to do a project like that I would pick a 351W or something.
I don't see why the Hi Po 5.0L would not fit in place of the Lo Po 5.0L, Bellhousing bolt pattern may be different (?)
As for the transmssion, not being an AOD guy, don't know, the dimensions may not line up, or they might!?.
Not sure what the rear end is, if it is an 8.8" or what. If it is not atleast an 8.8" I would want to swap one in. With all that weight to push you could break something easy.
Overall I wouldn't do it, but projects like this are always subject to personal taste!
