If I had to step over to the dark side, it would have to be a big block as opposed to the bellybutton motor. JK I know and understand the 350 willgive you the best bang for your buck. I just wish I had a buck for every person that has come up to me at a show or wherever I have my truck and say, "I had/have a truck like that and we swapped the 6 for a 350". I you take count at most shows, there are 20 bent motors for every inline.
Anyway, I think a big block would be cool. What do ya have planned for the brakes/tranny/rear?