You may also want to check your timing--it the timing is retarded the engine will have to burn more fuel to produce the desired amount of power. I have '70 Chevy Impala that the P.O. set the timing with the vacuum advance hooked up. It just never seemed to run right--I even rebuilt the carb thinking there was a passage plugged up somewhere limiting the fuel available. I ended up checking the timing on a whim and was VERY surprised to find the timing (with vacuum advance UNHOOKED) to be 3 degrees AFTER top dead center. I set the timing to 8 degrees BTDC, and reconnected the vacuum advance. I was then able to set the idle mixture and speed properly and let me tell you that car runs MUCH better--LOTS more power and much easier on fuel. I also used to tighten the exhaust pipe donuts at the manifolds (ram horns) every month and I couln't figure out why they kept getting loose. After the timing was set correctly, the donuts have not leaked since--and that was 4 months ago. My guess is that the manifolds were getting VERY hot, which was deteriorating the donuts.

Good luck, hope this long winded answer gives you some ideas.

Now I'll have to take the Impala back down to Fred T's neighborhood and show my cousin's friends how a properly tuned small block in a beat up brown Impala will really run.

Remember 9-11-01--God Bless the USA
JUSTICE, not REVENGE, will prevail

1951 Chevy 1/2-ton Pickup truck