I assume the trickflow website didn't have them. The other option is to ask the question of one of the HUGE american on-line sales sites like
www.jegs.com or
www.summitracing.com They are very helpful with tech data on products. And they reply within a day or two.
The real reason for the reply is i need a set of 460 heads ported and just wanted to know what state you live in and how much you charge?