https://www.summitracing.com/parts/m...iABEgInZPD_BwE
I used this on a 350 Vortec that had cracked heads, it worked great. I was told to try that by a machine shop owner, he used it on a 400 SBC dirt track engine that he ran for three years before he over revved it and put a rod through the side of the block!