360 Idle Quality

Bewy said
That timing for idle is not high at all for that combo. My engine idles with 48*. You may need more than 32*. The people saying check for bal slippage do not understand the requirements. A 440 I set up two weeks ago, man trans, 13-14" of vac likes 44* at idle. Your low comp is a big player, not helping, but it does make the engine want more timing.
Advancing the cam might make a small difference, but not worth the trouble in my opinion.
Use an adjustable VA unit connected to manifold vacuum to get the reqd idle timing. On the 440 mentioned above, I found the spring in the VA unit was too stiff, even on the softest setting, to work reliably. I took a softer spring from a HEI VA unit & fitted it to the Chrys VA unit & it now works reliably. If you use MVA to provide more timing at idle, you MUST make sure that the VA does not start to drop timing when put into gear...& cause erratic timing/operation. When I hear MVA didn't work for me, this is the number one cause!! NOT MVA!! Easy to check. Just put a Tee in the vac line so that the VA is connected & watch the plunger move.
More on the importance of idle timing...

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VA is hooked up to manifold port on the carb. I'm not worried about too much timing at idle. In park, the timing is 32 initial + 16 VA = 48 total. In gear, I loose most of the VA, thus the vacuum and rpm drop. I bought the B26 vacuum canister to try to keep the VA pulled in when idling in gear. I haven't put it on yet because it is somewhat of a bandaid fix. If I end up advancing the cam, I may be fine with the current B22 canister. I looked at the Pertronix adjustable canisters, but it seems there are quality issues with them, so I stayed away.

My concern with continuing to advance the timing beyond the 32 initial is detonation when the mechanical advance kicks in under load at higher rpm. I have the mechanical advance limited to 16, but that puts total advance at 48. That's what scares me a little.

I have a T in the manifold vacuum line with a vacuum gauge under the dash so I can watch what's happening.