I also switched to newer throttle linkage because I never could get my 2 barrel to open up right with the linkage from 79/80 (like yours). get someone inside truck while its not running to floor it while you look into carb to see if 2nd barrel is opening right. I removed stopper (governor) from behind accelerator pedal first, still wasn't great. Finally put newer accelerator linkage setup and it adjusted out nicely.

M

 

Only question I have now is, do I plug fuel return line going back to fuel tank?

 

I plugged the fuel line that returns to tank that is paired with a brake line. you aren't talking about those yellow lines off pump right? you have three nips on fuel pump two go to tank one to carb. I left all that alone. but I had another fuel line that was paired with brake line down frame and I capped him.

 

moved