It's entirely possible that someone somewhere along the way swapped carburetors out on your engine. But the stock 1bbl for the year of the truck would have been a holley. and again for the year of the truck it was possible for it to have come with a Carter carb, but for that year the only Carter that Dodge used was a 2 bbl.

OK, then. You've visually confirmed that it is a single barrel, so "we" all KNOW that the truck has been modified from original.

I'll leave the tech response to those that know more about the lean burn system.

Roger

Rodger thank you so much for your help. I have had nothing but problems out of this carburetor. I am going to do the lean burn conversion what carburetor do you suggest?

It has a one barrel Aluminum Intake

That model carb was always regarded as being better than the Holley that would have been stock. Maybe find another?