B Block in an A body...only 2 ways to go, underchassis or fenderwell...pluses and minuses to both depending on street driven or not. Some people drive fenderwells on the street but the exhaust system can be unsightly but the maintenance on engine/trans components is far easier than underchassis. Underchassis are somewhat "cleaner" from a traditional engine compartment standpoint and exhaust system is easier but install and maintenance on engine and trans is a NIGHTMARE...IMHO...TTI's underchassis are what we have on our BB Duster...nice headers...but wholly jeez!!! And don't even ask about starter R&R...