So now I'm chasing 2 issues. Now I have a whistle under load at about half throttle and the full-throttle stumble I was chasing.
Last night I took the street avenger off my 62, put it on the truck, and both issues persisted. So it seems I'm not chasing carb issues after all. I was ready to buy a new carb but glad I didn't.
For the stumble, I'm going to use a temporary fuel tank (Jerry can) with fuel line direct to the pump. If that solves it then I'm betting my issue is the rubber line in the tank collapsing.
If it doesn't... Maybe distributor? (everything except coil was replaced last year)
For the whistle, I'm thinking it's either a bad vacuum hose connection to something OR the aluminum manifold has a very tiny crack.
When I find whatever the issues are I'll be a hero in my own mind. I the meantime, it's slowly killing me.
Oh yeah, my fancy valve cover gaskets from TA performance are leaking for the second time, so they're about to be replaced too. It's a good thing I'm not paying someone else to troubleshoot this crap.