After taking my EMI Thunder exhaust off I seen some gold and white (calcium like) deposits in one of runners and in head. I thought that it looked like water was seeping through but I pressure tested the manifold and seemed fine?! I know pics would help alot but I dont think I can post. Does this sound like water reversion? If so why in just one cylinder? Would a leaking valve cause this? Its just a 502 w/ 500HP cam shaft and carbed.

sounds like reversion. Yes, a leaky valve can cause it. The HP500 cam is prone to reversion. 110LSA.

What risers do you have them?

I just now they are Stainless, 9" tall x 20" long?