I have a 305,700r4 with the q-jet but replacing it with a edelbrock 1406, ripping out all emissions and I know the booster connects to the back and I got pcv in the front middle, but there's 2 other little vac ports in front on each side I think ones a ported and one is a constant vac that I've found from researching, but the q-jet had like 6 vac lines out of it. Wondering if all the lines from the q-jet were for emissions? Or do I just cap the 2 on the edelbrock or is there something I got to connect to it from the q-jet set up? Sry this it's my first carb swap. And thanks in advance.

 

Should run dizzy vac advance to the ported vac. Everything else to manifold vac. Least that's now I would do it.

 

Vacuum advance goes to manifold vacuum in my opinon. Ported vacuum is an emissions era crutch and a poor one at that.

 

It goes both way . My msd dizzy said run it to ported vac. I don't even run vac advance if that says anythin .

 

Vac advance is a very good thing for any street use engine, and street/strip type cars really. Ported or full vac is a long time debate.. I find it best to try both ways for a while, maybe 20-30 miles if it's a weekend car, a tank full of fuel if daily driver, or 4 passes at the track if race only.

Use the vac source that gives you the best all around results.

I will say this though, most of mine likes full vac better than ported/timed.

Using vac advance will get better fuel mileage, clean up the idle some, keep plugs cleaner longer, can help you to get a big cammed engine running/idling better, give you the high timing you need at idle and part throttle w/o the worry of detonation at WOT due to, too much timing, etc.

 

Yeah I know it improved gas mileage but being a weekend warrior I wasn't to concerned with gas mileage.