I've actually already found my answer, but thought I'd share this. I went to look for numbers on the the Q-jet that came on the second OHC Pontiac L6 engine to determine the original application, and I didn't find any numbers, at least not in the usual spots. But I was surprised to see it made by Carter. Checking the other two Q-jet's in the basement, they both say Rochester and have numbers where I expect the numbers to be. First time I've ever seen this, and thought I'd share.
I've got a 67 Carter Quad core sitting at home...threw me for a loop first time I saw it too. From what I understand the demand for Quads was so high in the early years that Rochester division couldn't keep up, so they contracted it out. I guess the Carters are a bit rare, but they're identical to the Rochester built ones. No idea if there's a premium on them though.
Carter made a LOT of q-jets thru the years of production. They were built to the same specifications as the Rochester units. Even so, the early models, till at least 1974 are much more prone to stripped out fuel filter housing and fuel inlet seat threads. The castings get really "brittle" with age as well. Pretty rare to see stripped out fuel inlet seat threads in any Rochester casting of any vintage. We see a few 1971 and older Rochester q-jets with stripped out fuel filter housing threads. The rate for the Carter units is at least 50 percent. Otherwise they are the same design, construction, and work just like a Rochester carburetors sporting the same part number.....Cliff
That's something I learned from posting this up on two forums. Some people were surprised like me, and others said they've seen them on several cars and posted links on how common they were.
