U&J Throat design

[Bryce S.]

I've got questions about styles of U&Js. The first is I've seen pictures and looked and have noticed the throat on some have 1 hole behind the throttle collar plate and some have 3 holes behind the plate. What would be the reasoning in the different locations of these? Also I've noticed the choke arms on some are different. Some have almost a straight arm and others have a large downward curve. I'm just trying to learn a lot about these.

Thanks,
Bryce

[Scott_Conger]

That plate is part of the economizer system. For FORD, it would have one hole, and it's alignment relative to the throttle plate is critical for proper performance.

U&J updrafts evolved somewhat through the years in ways which are not always obvious. Due to their being modular in design it is quite possible that many "marriages" took place in the repair shop over the years. The most noticeable difference in them is the throttle shaft either being in line with the manifolds for FORD application, or cross-ways for Overland and others.

With respect to choke arms, (EDIT for correction) the sort-of-straight arm is an earlier arm and the curved arm is a later version.

(EDIT for addition) The economizer holes (3) which show up at two slots on the economizer plate is also an earlier version...later versions have a single, larger hole that is exposed via a single slot on the economizer plate

Note: a number of accessory carbs popular with "T" people also came in versions for the Overland as mentioned above, and in every instance they vary from "T" specifications in subtle ways. Purchases off of eBay and other places need to be done with a critical and educated eye to ensure you're getting what you really want.

the above EDITs are due to my speaking with Bryce while actually holding a very early and very late U&J in my hands while we talked (and further cementing the fact that my memory is not as good as I'd like to believe).