Ok, Ive come across 2 sets of heads I'm thinking of purchasing. 1 is a set of regular GT40 heads off of an explorer. The other are a set of stock 302 heads, that have been ported and have 351w valves. They have 1.94 intake valves and 1.60 exh, and they have 550 lift springs, but he doesnt know what brand. He says they have been professionally ported. My question is, 1 which will make more bolt on HP, and 2, can the 2nd set, the ported ones, be used with stock pushrods and cam? I need to know asap so any help will be greatly appreciated, thanks.