air intake question

Alright, I got a vacuum gauge hooked up this weekend, and at idle ~700 rpm it is pulling 15-16 in-hg. That seems a little low (20 in-hg is nominal, correct?) I was able to get the vacuum reading a bit higher (17-18 in-hg) by advancing the timing...but it is REALLY advanced...i don't think I have heard any knocking, and it seems to run okay, but 20*+ of timing at idle seems excessive. Anyway, so I thought I might have some vacuum leaks.. Couple questions:

1) how much air should be pulled in from the valve cover vent on the passenger side, the one that has a hose connected to the back of the carb? If I pull it out of the valve cover, it seems that there is a ridiculous amount of air being sucked in there and if I cover it off completely it makes the engine bog quite a bit... Could the valve be bad and therefore throwing off the A/F ratio and causing low vacuum?

2) Where can carburetor rebuild kits for the stock carb on the V6 be found? Just trying to cover my bases...

3) Any other likely sources of vacuum leaks? I torqued the intake manifold bolts to the FSM spec..and made sure that the carburetor bolts were tight...

Thanks guys!

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Bumping, I bought a new PCV valve last night, haven't put it in, but we'll see if that helps. Any answers on where to find carburetor rebuild kits?? Thanks guys!

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If you have the original heater in the jeep, some of the vacuum lines going to the heater controls under the dash may be loose or broken. Mine were bad where they attach to the controller. If i remember right, their are 3 that attach just beside the fan switch.

 

Hmm, and that would be enough to make the vacuum read low? I will have to check that out.

 

Alrighty, thanks Sparky! I managed to find where you posted the link before. The point gap is set exactly to spec (30*..at least according to my dwell meter..), the timing as I said originally was set slightly more advanced than spec (6-7*) so I think that that leads to the carburetor and/or what lamar said and/or other vacuum leaks. Looks like there aren't too many pieces to the carb rebuild kit, the rochester pretty easy to rebuild? Good thing I enjoy this stuff...otherwise this could get frustrating fast! Thanks guys!

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Does the kit come with instructions? I suppose that it is somewhat covered in the FSM, I haven't looked at that section extensively yet. I figure for $24, its probably worth doing.