B engine in early Valiant

I'm building a 64 Valiant, currently a 273 push-button. I have 2 B blocks, a 383 and a 400.No tranny for these,but I have a bell-housing from a 69 or 70 B-Body. On the small block side there's a roller cammed 89 360 in a truck, and an old 340 crank at my disposal,leaving the possibility of a de-stroked motor or buiding it as a plain 360.This combo has a 727 behind it,but it sat for a long time and is weak. Anyone who has done this early swap to a low deck big-block?Or would a tall deck motor fit easier? I'm not a big fan of cutting the inner fenders for my exhausts.Would a conversion to rack & pinion at the frontside of the K-member work? I've seen these advertised,just not for the early A's.Both B engines will need bored,but are complete,and I do have one good set of 452 heads.The 360 under consideration has swirl port heads, and does run. I've even considered swapping TBI fuel system and all. Has anyone opened THAT can of worms? Anyone know if they make a "hotter" computer or chip for that system? Any help would be appreciated.Thanx FABO!!! Bruce 8)