I have a set of tms main caps, they are very nice. I have a customer doing well over 1000hp on a early 7m block with the 6m crank. Stock caps. He is however moving up to the billet caps. I would put them in any 7m motor doing 700 plus hp like Sean mentioned. Thats just me. Its not so much the rpm, its the force of everything pushing down under high hp use.