Correct, aluminum only. plan is 290 ish, we have a prototype doing it. There are experts on here getting alot more out of SB mopar heads, but again the idea is to keep these mainstream, and not cross into exotic. My in house testing on the airgap imports is they scrub major HP. I'd like this to spawn a "bigger" single plane version of our 408, so needs to have LA bolts. THANK YOU for the feedback.