Distributor question

[turnpike boy]

At present I use a straight-mechanical advance distributor (MSD) on my little motor (331"). This was done primarily to avoid detonation issues - better timing control - and because the motor runs right around 10.4:1 compression. I have been thinking lately, however, that the benefits of a vacuum-advance unit (like better mileage) might be a better choice - but have some concerns about that hi-vacuum, part-throttle condition and the potential effects on detonation that the extra 10* or so of timing might give rise to that.

So - can anybody give me some good advise/realtime experience with vacuum advance dizzy's with moderately hi compression ratios and normal, every-day gasoline that's available these days?


-Roger