Well I looked up the number on the tag you had , and if it was all original that should be the correct carb for your vehical. It is a r2-2g.They used that carb on chevy and gmc's p/u's from 63 thru 67. As for your no gas upon accleration as you state,you could have a plugged acclerator port from your float-bowl area to the discharge area. That is under the 3 screw venturi port on the main body. Or most likely you are missing the 2 balls and maybe the spring on the acclerator port! Did you soak it in carb cleaner? Napa sells a 1 gallon can with a basket in it for this!! Make sure and blow out the ports!! Here's a really good link on you tube to help with your problem.
This is part 1 the other parts are on you-tube for the entire rebuild!! .
Good Luck!!!
Chuck