"new wider seats"

I didn't mean for this to be any big deal, just a little wider than stock when the shop grinds the valves to help carry off some of the extra heat generated by a blower.

"for the extra 100 I can get new world heads"

Please explain what's going on here. Extra 100 over what??

"They will mill down a set of vortec heads for $90"

Please explain what you mean by "mill down".

" If I get a set of vortec heads how much do I need to mill them down to make them work well with my Weiand 142?"

Again, what do you mean here???? If you're talking about cutting the heads to decrease the combustion chamber volume, STOP. You don't understand the basics of supercharging. Purchase this book immediately and read it cover to cover....
http://www.amazon.com/exec/obidos/tg...books&n=507846