Holley makes plastic replacement caps to check the float levels with the car running.
No mess
I don't recommend them as a permanent replacement for the steel ones.
Double check the pump shot from the squirter in the front, sounds like the arm may be adjusted too loose, you need to check the gap with the throttle wide open,
Holley's are easy to work on and tune, but I also had one a few years ago that with the help of everybody here it was just JUNK and it was a fairly new used one.
OldmanRick is super knowledgeable on Holley carbs, he actually taught me alot from his posts here.
