spark plug heat range questions.

pjc360 said
Can running a spark plug with too high of a heat range cause idle problems

No.

running vaccum advance off of manifold vaccum

That can certainly cause hiccups and skips in the idle. Why not run the vacuum advance the way it's supposed to be?

maybe i could get this thudding or miss to go away while at an idle with a colder spark plug.

Nope.

Is it possible that maybe the plugs i am running are too hot and that they are causing a miss at idle?

Nope.

I am currently running Ngk v-power spark plugs the zfr5f-11's

Try ZFR5N.

the next step colder plug would be the zfr6f-11

Yes, if you want to stay with the present spark plug configuration but go one step colder, the ZFR6F-11 would be the one. But how are your spark plugs reading? That's what will give the answer to whether you need to go to a different heat range.

i could get away from the ngk's and run the autolite

That would mean going from high quality Japanese made plugs (NGK) to cheap Chinese garbage (Autolite).

Is it worth trying a 1 step colder plug and seeing if this issue goes away?

No. Waste of money.

Currently i have my vaccum advance running off of th ported vaccum source on the carburetor , but i have een told this is wrong and that it needs to be on manifold vaccum

No, it should be connected to the ported vacuum nipple on the carburetor. That's what it's there for.