Pete, I don't have a lot of Rochester B's to look at, but a 7003526 (1952 - 235) has manifold vacuum. I have a few more B's in storage (have been quite unsuccessful in my B giveaway campaign), but cannot easily get to them.
I looked at a couple of YF's (both 216 and 235) and they have manifold vacuum.
Are you absolutely sure the 235 is supposed to have ported vacuum?
All of the W-1's (1949 and earlier) I checked did have ported vacuum.
Bill is correct about United; they were an independant rebuilder out of Chicago.
Oh, and one other thing: Unlike the Rochester, MOST (not all) Carter YF's have the part number STAMPED (NOT RAISED) on the center section of the unit.
Jon.
