The brass guide which is round with the slot was used in the 1950 carburetors. 1951 and newer carburetors use the "T" shaped guide (there are two different of the "T" shaped ones). This is one of the problems with the "one kit fits all, but doesn't fit any correctly". The proper kit should have the correct guide.
"Rochester Carburetors" by Doug Roe and Bill Fischer, published by HP Books has a small section on the Rochester type B. The original Rochester type B service manuals, while obsolete, are still available from some sources. Try a search on the internet; watch ebay, check swap meets. For the type B, these are better than the Doug Roe book. For later two barrels and four barrels, the Doug Roe book is required reading.
Jon.
