[davepl]

I'd send it to Carb Connection in Kirkland WA or some other expert QJet rebuilder. I've also had moderate luck with Stage II Qjets from "Jet", but have also heard that the rebuilders get a lot of them fresh off the shelf to be redone.

Anyway, QJets are such a flexible carb that pretty much anything will run with any QJet, but to run well or properly it's going to need a knowledgeable tuneup whether its new or rebuilt. Besides, even if rebuilt perfectly to factory specs or replaced with an NOS perfect one, fuel is different than when they built the calibration into them 40 years ago.