Vacuum line help

[harvey85]

Alright, I have an 85 C10 with a 305 and an electric quadrajet. Engine turns on and off fine. The PO took semi decent care of the truck however, the carb has a lot of vacuum hoses disconnected or non existent. There are two vacuum lines connected on the carb, one on the front lower drivers side that runs to the canister and one on the rear lower centerline that runs up by the cruise control. As I fiddled around with the engine running I put my fingers over the tee coming off the front passenger side and the idle decreased notably. It also threw a check engine light probably related seeing how it wasn't there until I messed around. If anyone could give me some advice on which vacuum ports I should plug and which should be connected it would be greatly appreciated. Also, I removed all emission control stuff, the egr was plugged when I purchased the truck. When driving it sounds like I have a exhaust leak replaced both flange gaskets and snugged down the hand tight header bolts but didn't seem to help, don't know if that's related to anything, just thought I would throw it out there.