While you have it running, spray some carb/choke cleaner all around the carburetor base and the seam where the top joins the body. If the engine revs change you have found your vacuum leak and likely point of warpage.
When the carb is off the car and taken apart, lay the mating surfaces of the parts on a piece of window glass and look for gaps. A metal straight edge works, too, of course but the glass method is a little easier
I will do that. This truck also has about a 1" throttle body spacer between the manifold and the carb. I noticed there wasn't a gasket between the spacer and manifold, so I added one. I also have one between the spacer and the carb. Is this the correct method?
