[Schurkey]

Originally Posted by Rx:GTO daily

This occurs after depressing throttle fully to set choke

Where is Cloud9 that it's so cold you need to fully depress the gas to start the car in May? I'd be expecting 1/4--1/2 pump maximum. Is your choke pulloff adjusted properly and functional?

None of that addresses the WFO problem. Any chance the carb/manifold is getting too hot under load so as to boil the fuel? (exhaust flow through the intake manifold crossover because of an exhaust restriction including the heat riser valve not fully open.) That's the only thing I can think of that hasn't already been mentioned.

[necdb3]

sounds to me like this is a secondary issue. I have seem these carbs stick after wide open throttle. the next time it does this take the air cleaner off carefully not to disturb the linkgage and see if the lower secondary plate is slightly open. It's usually the linkage that connects the primary to the secondary that would be binding

Dave

[Rx:GTO daily]

Thanks guys! Malky: No gas in ram air pan... all of it is outside pan (on carb and manifold). It is either working it's way between pan/gasket/carb, or leaking from the pan's drain holes. The carb itself is not leaking. The ram air pan is just a fancier snorkel base... serves the same purpose. Also, due to throttle position causing this problem, I planned on checking choke assembley. Shurkey: Agreed, seldom need full depression of pedal for choke... can't say I don't press it that far though without thinking. No heat riser... headers. Vapor lock/boiling has never been an issue over the years with this car and this exact same setup. Doesn't mean it couldn't be, but has not been. Plus exact scenario happens at cold start.. occasionally. I also use heat resistant and steel braided racing fuel line from pump to carb.
necdb: I want to check that also... should be able to view linkage without removing pan... hopefully. Then won't have to disturb anything!
I am also super careful to never tighten aircleaner nut any more than is necessary to just hold everything in place.
Thanks again all!!