Hello, still somewhat new here, but I have a question. I have a 75 K5 with a 350 sbc. Somewhere down the line of ownership, previous to when I got it, the heads on the engine were swapped out for a set of centerbolt 87+ heads. I looked up the #'s and found they are from a 305, meaning slightly smaller intake valves (1.82 ish as opposed to 1.92 ish) but they are Vortec (swirl ported) heads. I am wondering if the "vortec" properties will outweigh the fact that it has smaller valves. It has good power and decent gas mileage. Does anybody know of any pros and cons of this setup? I have the intake and headers off as we speak so this would be the time to do something about it. Thanks for any input anybody might have.