I have both BB and SB powered mopars and both run very well. The Demon with the production headed, [587 castings], sm block, flat tappet cammed, stroker 360/418 has gone 9.68 at 136mph with a 1.26 60ft. at 3100#, on gas. The LeBaron with a production headed, [915 castings], Big Block, flat tappet cammed, stroker 383/449, has gone 9.02 at 149mph at 2450#, also on gas. They both have equal effort, and cost, in building them. The BB runs a little hot and the sb runs cool.
I have also had the guys walk away in disbeleif after seeing the Demon go down the track and then see the stock appearing sm block under the hood
An all iron sm block munching an all aluminum big block