Tim's stuff is really awesome. Note he has an option that eliminates the standard gaskets by leaving .060 more on the intake flange side, and there are other things he does to them. And as I mentioned before, everything has to match to make it work....He has a whole combo on his site for a pro-street 572 and bigger.....Check it out. He seems to have it down and a lot of guys like his stuff. He uses a different set of keepers and valves than a typical Hemi as well. All his stuff is pretty well sorted out. Pick one of the builders and get all your parts from one source so you know it matches up.

471 flow is a really good starting point for a big engine with a lot of cam, most of us are in that range or a little less. My heads flowed 458 or so.