Vacuum leak

[rclayton12]

I think I may have a vacume leak, where do I begin to check, and how do I tell. The car seems to cut out and the RPMS will jump up occasionally. Also part of the problem may be that spark plugs in cylinder 5 and 6 seem to foul out quickly, what do I need to adjust. Also would a valve cover gasket leak cause this?

-73 240Z, flat top carbs, monza exhaust, omni spark wires

[Zedrally]

Arm yourself with a can of RP7 or WD40 and with the engine running, spray a small amount around the inlet manifold, start at No.1 and work backwards.

If the manifold gasket is leaking, you will notice a pickup in engine RPM.

Valve cover will not cause this....