NM51, Thanks for the reply
First I'd like to say I hope I'm not under estimating all the folks switching to an HEI distributor. The HEI is a great distributor, faster starts, more spark, and no points. Well worth the effort to recurve it.
NM51, This 442 link is a good one,
http://www.442.com/oldsfaq/ofign.htm#IGN%20Tuning A pretty complete discussion on recurving including how to check the results yourself and adjust.
The distributor data in my previous post is part of what I have from my shop manuals, and I'd like to add a few more. I've put the data in a spread sheet and looks pretty obivious that starting in about 1968 GM starting limiting the centrifrugal advance and vacuum advance in some years the vacuum advance was increased. That's why just putting in an HEI may not get what you want. If your performanced minded then the HEI needs to be recurved. Just putting in a recurve kit is not the answer, it could do more harm than good. The 442 link is a must read. I have a distributor machine and intend to some more work with distributors as soon as I get done with my 292. The 292 is the next project on my list.
Larry
