Ron, didn't you have a problem and posted 06/08/18 a question about replacing them (dual Rochesters)? You were getting 23 MPG (2011 Gallery update) then it suddenly dropped to 15 MPG? It may not have been the same posting but I recall you took the truck back to the shop to have them work on it. I'm fuzzy here. Didn't they install a new kit or something like that. Your first big trip was 2009 so the first rebuild lasted maybe 10 years? All in all, that's pretty good service for old Rochesters. Why not post a picture of what your carburetors look like today?
Before comments erupt about the 23 MPG, Ron has a T-5 transmission and 2.73 rear axle. On mostly expressway driving (no mountains) at lower RPM and carburetors working well, good engine, he can ring out the mileage.
I believe that Ron discovered that he indeed did not reach 23 MPG. I hope he comes in and explains what happened that made him believe that was getting 23 MPG. He has posted it in the past, but I don't recall what it was.
Personally I don't think that you can get a whole lot better than 15 MPG in these trucks even if you only drive down hill with the engine off.
