340 to 416 stroker build need advice

I would sell the x-heads and go with closed chamber Edelbrocks fully ported. Zero deck the pistons and run some 1008 Felpro .039" head gaskets for a tight quench. I would run ARP main studs with the block line honed. It doesn't cost that much and it will keep that bottom end tight. I like the Scat I-beam rods because they are light and my machine shop really liked the way they measured out. And you don't have to clearance the block with those rods. I have heard a lot of good things about K1 cranks. I would go cast steel for what you are trying to do. One advantage to cast is it is lighter which means it will rev a little quicker.

A 4.04" bore is just a .040" 360 bore so pistons will be easy to get. You will have to have a machine shop look those bores over before you order pistons because you want to get the piston to wall clearance correct. It might already be honed too much and need to go 4.060" (.020" over) which is what mine is.

As for cam I had Brian at Indio Motor Machines grind me a custom hydraulic roller for mine. crackedback can give you his contact info:

http://www.youtube.com/watch?v=0DH1DRzAVZI

As far as Hughes I don't trust them. That is just my opinion and nothing more. They sell good stuff but you just can't trust everything they say. They don't always look out for the customer's best interest.