Rpm/speed problem

[HTX86chevy]

Truck Sat for two years.
Ran great before it sat in my warehouse. A month ago, I decided to start using her again. Truck would not stay on at all during idle but ran fine as long as I had the gas pressed. Rebuilt the Carb (edelbrock 1406) and now she cranks, Idles and cruises fine. Since pulling her out of storage, I have done the following:
Oil and filter change. Carb rebuilt. All three fuel filters replaced, pcv valve replaced (it rattled during idle) .... and thats it.

Problem: truck cruises fine and picks up speed gradually. No problem hitting 80mph gradually. I can't get the RPM's to rev passed 2200 though. If I put the gas to the floor it only gradually picks up. She used to burn tires a couple years ago and now feels like I'm driving a station wagon.

I guess what I really want, is a point in the right direction. What should I check 1st?

Thanks in advance.

[HTX86chevy]

Replaced all 8 spark plugs today. Absolutely no change.

[78 Big10 454]

Check your exhaust system. Bad catalytic converter or other restriction.

[HTX86chevy]

I figured it out. Thanks for your help. If nothing else comes from this , at least I learned how much of an idiot I am.
When I installed the carb I pinched a spark plug wire with the back end of the carb. The cable was completely cut in half but still smashed inbetween the carb and instake. This was causing a misfire in cylinder #7 and preventing the carb from seating correctly in that back corner.