I just put a new carb (stock) on my 76 20r engine. the old one had 2 vacum line outlets. the new one has 4. i plugged 2 and ran 2, vacuum advance and one to the box.It runs well on the road but i cant get the idle right. it will idle at about a thousand rpm fine. any lower than that it sputters and dies. i've dialed in the fuel mixture, and advanced the timing to where it should be at the higher rpm. no vaccum leaks ican find. am i missing something with those 2 extra vaccum ports??? I cant find a vaccum line diagram anywhere, any body know where i can find one of those??? any ideas ???

 

For a vacuum diagram, as well as more carb info, you need a Field Service Manual, or FSM. A good google search might find one available for download online, or here is a post referencing a source to buy and download FSM's online:

https://www.yotatech.com/forums/f16/...-engine-36688/

Good luck!