Taking into account the weight differences of each engine in the same car, the power differences are not huge and the gains will be small. The B engine will always win. Even with the weight penalty.
I can agree purely in the terms of "racing" In a street car id probably go with the LA engine. You don't need power accessories cruising the 1/4 mile,and again in terms of A body. I had a B Body Coronet 500 back in the day with a 318. it was a nice car, and I would have liked it more with a 383 -440.
i do know big block people back in the day who wouldn't even play around with the LA engine. I had a friend who would call me and say "hey want this 360? come over here and get it out of my garage..." :)
