HEI Advance curve:
I am hoping someone can help me out, after reading a article on changing the advance curve on a HEI distributor (http://www.boyleworks.com/ta400/psp/distcurve.html) I need some part numbers: The GM part number for a #398 center plate and a #139 weight also the bushing for the weights. The local GM dealer has no listing on these parts separately (only the complete shaft assembly). Can anyone out there help?

Mechanical advance begins at 900 rpm and increases as follows:
rpm Degrees rpm Degrees rpm Degrees
1000 6 2000 13 3000 17
1200 9 2200 14 3200 18
1400 11 2400 15 3400 18
1600 12 2600 16 3500 19
1800 12 2800 16

Figure 1: Results using a #398 center plate, #139 weights, and moderate springs.

You need Accel Kit Nos.

31041 Advance Curve Kit

31035 Adjustable Vacuum Advance

JEG'S or Summit

Thanks Kultulz, that is what I am currently using (not got the vacuum advance yet) but I am not completely satisfied with this kit and would prefer GM stuff if I can get the same or better results also to quote the above mention article: “most aftermarket curve kits of weight and springs, and a center plate are not very accurate and may provide a poorer curve than what exists. (The medium and heavy springs in these kits can be used with stock weights.) .

I know this is one person’s opinion but look at and feel the GM stuff and the way it fits compared to the aftermarket stuff. But thanks for the in put and I do plan on getting the vacuum advance unit.