So what does this do?

[MilkyJoe]

Hey guys, just put a 'new' carb in my truck and it runs a LOT better, but still has a little hesitation when giving it gas, timing and carb are set perfectly.

My friend (mechanic) said the vaccum advance is bad

He hooked a pressure guage to it and it leaked out. wouldn't hold.

Would this make the truck lose its gusto?

Truck will cruise and drive, you just can't floor it or it will start stuttering.

I priced them and they are about $12

how hard are they to replace?

Sorry for playin 20 questions but I need the truck running as my newer Monte decided to blow a fuel line on the way to Louisville