Have any of you tried setting timing on 350 Chevy using Vacuum Timing method?? ( Where you set timing for max. or optimum performance by measuring manifold vacuum) What kind of results did you get??

I have not tried it on a Chevy 350, But I do run and Chevy 4.3 with a 471 blower on it and the only way that I could get it to run right and not ping and rattle was to lock out the mechanical advance on dual point dist. and set timing to max vacuum and fatten up the air fuel ratio.

I have used this vacuum timing method with success.

1. Set idle screws and rpm to factory spec.

2. Advance distributor until you get the highest vacuum reading.

3. Back up the distributor until you get one less reading. If 20 was your highest reading, turn the distributor until the vacuum gauge gauge reads 19.

4. Lock your distributor down and test drive the car.

That is "old school" and it still works today.
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The "New" and Unimproved edcroozer... Charter D.S.R.A. member, WPoC member and general pain in the neck to the needy. Possible daddy of Mr.Willys, and still Al Liebmann`s good friend.

on non computer engines I unhook and plug the distributor vacuum then set the total mechanical advance at 34 degrees with the engine at 2500 rpm (or whatever rpm the mechanical advance reaches its maximum). If the initial advance is then too high then some work may be required inside the distributor. Usually I end up with 12 to 14 degrees initial advance at idle which is ok in most curcumstances.
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KEEP THE GREAZY SIDE DOWN! Lobucrod