I just finished addressing this issue on my 77 it turned out to be a vacuum leak that would be where i started looking

 

does your carb have wires hooked up to stuff on it? if so i think you might have a 6280 which would have come with the lean burn system which sucked and may be the cause of all your problems. from what i can tell the 2280 came on vehicles that did not use the lean burn system.

if you have the lean burn system then a carb rebuild will most likely not help.

 

Thanks for getting back crazzywolfie. I kept googling and came up with a thread on a different forum http://www.vannin.com/threads/ubbthr.../356448/2.html here. My carb looks pretty much identical to the one in the photo for the 2280 in here. I checked and the ONLY wires I had to unplug when removing the carb were the idle stop solenoid wires (two or three wires, plugged into a receptacle on the passenger side near the front of the carb, there were no other wires going into the carburetor). These wires only went to the ISS and not into the carburetor. I want to say my truck, since it's an 87, has the lean burn system. Lots of vacuum ports are plugged and it looks like the previous owner did a little bit of his own stuff before I bought the vehicle though. I'm starting to think now it's a 2280, since there aren't any wires going directly into the carburetor. What do you think? Did they try converting it? Is this one of those hybrid cars that people screwed up when trying to go from lean burn to non-lean burn?

 

yours is most likely a 6280 then and lean burn. it think 2280 does not have a idle stop solenoid at all.

if it has lean burn there will be a computer on the air cleaner or hiding behind the battery.

 

Believe it or not...started taking it apart and I realized it was a 2280 instead of a 6280. I had to compare diagrams of the 6280 and 2280 and finally I found that my carb was exactly like the 2280, every small part and such.

NOW here's the lame part. I decide to take it apart for a re-build. I'm disassembling it and I get to the main jets. One of them screws out piece of cake, the other one I started having a tough time with it. Since I figured I could get a new jet easily at O'Reilly's or a shop similar (I QUICKLY FOUND OUT THIS IS NOT THE CASE, sucks to be a novice with carbs) I figured I could keep trying to get the left jet out even if it sacrificed the head of it a little bit. Long story short, the jet's pretty much destroyed, still stuck in the carb (I'm just gonna have my buddy at a machine shop ez-out it for me)...basically I'm now down a 2280 main jet. I looked online and these seem hard to find, does Holley even have a cross-reference anymore for the newer jets that can be bought on their site with ones from the old days? Yeah, some lessons are just learned the hard way and I feel like an idiot. I'm two steps away from donating this truck to the local junk yard.

 

I was having the same problem with my 82. Talked to a mechanic friend after I rebuilt the carb and he suggested switching to the carter 2bbl. Just swapped it today and truck runs like a dream