[1968GTO421]

After reading these posts I found Wagner's page of adapters ( https://mewagner.com/?p=540 ) where they have a valley pan adapter designed with help from Jon's Tri-power Service which looks feasible for most Pontiac applications. I looked closely at David's photo in post#6 and think that the Wagner just looks like some of the goofy smog stuff of the late '60's-early '70's that our engines had back then. I agree the appearance sucks but if the flow is good and adjustable, it could be very feasible for a rowdy camshaft. THe cost is not good but a re-build kit is availble so that mitigates the cost somewhat. And post#17 points out correctly : " I don't really trust what I am getting at the store any more ... seems like part numbers have been consolidated. I have about 13" of vacuum at idle so figured it was worth a shot to use the wagner valve instead of risking getting a pcv valve that was not calibrated for a lower vacuum application. "
Post #11 points out the use of the std 4.5 cfm PCV valve for the car makers has worked for years.

I appreciate all the responses to this thread. Much to think about here before making a decision. Thanks y'all.