Don't know which raised port heads you are talking about, but i put Brodix 10's RP,FP's on my 434" and Hilborn 2 7/16" stacks.
I had too build 1/4" spacers between the bottom of the manifold and the front and back top of the block, also had to use .120 thick intake gaskets to get the ports to line up.
These block spacers are availablen the web, but i made mine since i had the equipment too do so.
Below is a pic. if you look closely the spacer is not under the manifold in this pic., you can see the gap.
Zip.
