I really have no idea, just seems like abad idea. Don't matter to me any ways. I'm getting a intake with the blower. I will be buying a blower cam. Just not sure what one. That's a bit down the road. The heads are fresh from the machine shop and the guy (he's a member here) only wants 300 bucks for the set so when I get the chance I figure I pick em up. The have to better than the heads on the block.