I purchased mine from Hensley Racing . About two months ago. Makes great power. Had a medium Port job done. Ken Hensley said they flow better than similar aluminum heads. Rpm etc. Before any work. I have the full Info. Somewhere.
74 Plymouth Duster , 312/590 mopar purple cam. Forged pistons, h beam rods. 1050 dominator. Hooker super comp. Headers.
440 30 over. After about 20 1/8 runs
Low 6.50s. I don't think it's realizing full potential yet. Made in USA.