With regard to the camaros.org/coolingsystems report. I have been looking into the question of just how valid the 68 part numbers are that are provided in the assembly manual (AM). I want to say up front that I think Kurt did a nice job on the his (CRG) Report and I mean no disrespect to him or the work with what I've put in the attached table for folks to review. While there are typo's in the AM part numbers I think that we can generally accept them as accurate until proven otherwise. I've put together a table of valves that I could find in the 68 manual and some support info found in the AM for each where I found it. Even though I can't find supportive info for each, as is the case for the Z28, I think that the fact it is in the manual is good enough for us to use for the hobby and think it's not unreasonable to utilize it in a list of numbers when "checking" valves.