Carb Question.. Help a Brother out....

[Mill Knob]

Well since its only at mid range rpm's and the idle is ok its not going to be as easy to figure out. The first thing I would do is try riching the mixture (thats presuming you put them in all the way then backed them out 1 1/2turns to start) by 1/2 turn. I would also double check the float height. If its low it can fuel starve at mid to full throttle.
You can also try checking for vacume leaks with propane or carb clean.
Check all your vacume lines (the ones down to the tranny, plus evap lines), accelerator pump settings, and air cleaner.
I hope this helps some, its easyer to diagnose with the truck in front of me.
Broncomatt

Thanks Matt for the help. I will try the fuel mixture. I will see what happens..