I go thru the good and the bad of these different heads I have tested and run thru the years. An opinion of how I see them and what they are briefly about!
Cover photo: SBF with raised port Blue Thunder Heads. Middle, BBC all aluminum 672 cid with GM Pro-Stock heads. Back engine, SBC Periphial Port all aluminum engine.

I get numerous requests for technical advice and if interested, tex me @ 626 203 2712. $100-Half hour to $150-1 hour+ rates. Most calls go over as posted and it is ok. US Pacific time zone.