Yes, NGK 5 heat range would be best. Using Manifold connected Vacuum Advance [ MVA ]. A reallllllllly good idea with
that cam.
But you have to get it [ idling timing ] right
first. You adjust the carb
last.
This is how you do it. Disconnect & plug the VA. Engine idling, in gear if auto, starting with the dist giving about 10-12* at idle. Turn the dist
slowly to advance timing until you have the highest idle speed. Now check the timing. My guess is it will be in the 20-35* range. Whatever it is, it is what THAT engine needs.
So let us say you got 26*. You can use
any combination of init + MVA to give 26*. If you were using 12* before, you can add 14* with the VA unit. You will probably need to make a stop to limit
total timing added by the VA arm. This is ALL part of tuning once you deviate from stock.
With this done, re-adjust carb idle setting. I doubt the met rods will need changing once timing is correct because running with insufficient timing makes the engine inefficient & it uses more fuel to cover the inefficiency.
Things to note:
-
you need an adj VA unit. None of the above will work with a stock unit. Even if you have to buy a new dist....
- adjust Allen screw in the VA fully CW.
- see below on idle timing
- the carboned up valves is from oil leakage past the valve guides, NOT richness.
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