i currently run a pair of stock l98 aluminums and have a set of 64 cc cast irons in the garage off of a 300 hp crate motor from 1999 with 10 miles on them they are new style castings but not the vortecs are these any better than the late 70's early 80's castings that were prone to cracking if so could i hog them out port the bowls and get decent flow out of them or should i stick to the aluminums.1.94 intake 1.5 exhaust

 

It's so much easier to work Al, than it is cast iron...besides, I don't think there are any CI heads on 300hp crate motors that can be as good as the ones you have.

Besides, the benefits of Al. are widely known...lighter weight and the ability to run higher compression and a maybe a bit more timing, without the fear of detonation.