I went just the opposite way. I spent almost enough money on "tune-up" parts and carb mechanics for the Holley 4150 as I would've for a new carb...and I never did get rid of a low rpm stumble...it would be fine one time then ran like crap the next.
I tried everything I could on the Holley...all the "tricks" etc. people would tell me...
Finally I bought a 4106 Edelebrock (manual choke). Put it on, went for a test drive, came back and did one rod and jet change an never touched the carb again until I pulled it off to change to Webers.
Good luck, hope you have better luck with Holley than I did
