Small Block & Big Block Chevy Specific - HEI distributor mechanical advance limits

I have a 383 crate moter that i am using an HEI distributor on. I need to run 35-36' total advance. the trouble is I need to run 15-16' initial to get the full mechanical advance. does anyone here know if the HEI is limited to 20' of mechanical advance? is there a spring/weight kit that offers more advance?


BTW i am NOT using the vacuum advance, I realize this can add advance, but at full load there is very little manifold vacuum to add advance.

The HEI distributors came with different amounts of advance built in. You can make changes to the amount of advance with different springs, weights, and stops.

It's been a while since I messed with an HEI so I can't remember any specific numbers, but more often than not, I found myself limiting the amount of mechanical advance.