I just disassembled the valve from my 12d 68 z/28 and it looks like gray phophate. Did anyone else see this on any early 68s before? All of the 69 ones I have seen are silver zinc. John
What was on the inside of the nut? How about the threads? That's pretty much sealed so whatever the finish was there sould be what it originally was...unless it rebuilt in the past sometime and was stripped. Also, did the outside have any traces of black paint? If so did it extend under the nut mating surface? Do you have any pic's? Just re-doing mine now too (12d los car!) and want to get it right the first time! Mine was rebuilt in the past and looks like they stripped it-there was no signs of plating anywhere on the nut and the entire thing was painted black and even had black paint into some of the threads of the nut-that's why I'm pretty sure it was redone.
Thanks for the reply & info.