Oh yeah I've been searching but the info has been limited. COMP quoted me about $835 for the billet core. So I guess it would be wise to err on the side of the largest base circle I can. Any potenial dangers in that? I would rather do this actually to raise the lifter high enough to prevent interference problems between the link and the block. Isky makes lifters with interchangeable link bars but only offer a mechanical lifter for this. BTW, why isn't a mechanical fuel pump compatible with a roller cam?