Are you talking aluminum block, aluminum headed big block vs. iron block aluminum headed small block?
From a post by JGC
"Hi all,
I just weighed my FE with all accessories, starter, flywheel, carb, expansion tank, and alternator. It is an all aluminum 482, Pond block from Keith Craft. No
oil or
antifreeze and it weighed 487 pounds.
I remember back when you wanted 1 horsepower per cubic inch. This is 1 pound per cubic inch. I am very happy with this. This works out to be about 1.4 HP per pound.
Hope this info is helpful,
JGC"