well kinda sounds like a stupid question... but i got most of it figured out.. im swapping a holley double pumper to a Q jet rochester.. the fuel line is simple.. the brake booster is easy also.. but for my vacum advance theres to possible connetions.. one at the base of the carb.. and another about 2 inchs above it.. wut would be a better vacum source? also theres one more port or wutever its called.. at the very front bottom at the bas in the center of the carb.. its a bigger connection.. is this for PCV ?? also theres one above it.. but it was not used cuz it has a rubber fitting holding it closed.. my PCV right now is directly to the manifold on my edelbrock performer.. i just not sure wut to do with the 2 choices for vacum.. and just close off the others i don't use?? thanx for the help on a dum quesiont.. hope u can understand wut im asking.. kinda typed this fast.. sorry guys.. thanx!
09-06-2003 02:49 PM
Not dumb qeustions at all. Use the port above the throttle plates for vacuum advance and the other will be used for anything that needs a constant source of vacuum. If you don't need it then cap it off. The big port in front bottom of the carb was used for the PCV valve. You can just cap it off as well.
09-06-2003 03:38 PM
perfect.. thanx man.. thats all i needed :thumbup:
09-06-2003 03:40 PM
If your pcv hose is going to your intake, i'd personally move it to the lower front large pipe on the Q-jet. If the location on the manifold is closer to one runner than the others, you will delute one or two cylinders more than the rest with crankcase gas. If you use the center port on the carb, the gases will be more evenly dispersed to all the cylinders.
09-06-2003 08:50 PM
excellant.. good point.. but.. if i do this how do i block off my manifold vacum?
09-06-2003 08:53 PM
You can use a metal pipe plug if its going directly into the manifold, or if its a pipe, just get a matching size piece of hose, put a bolt in it and push it on. Not the most eye appealing way, but works!