Chevy HEI Distributor problems

[vettestr]

George thanks for the detailed info. How useful is a vac. adv. unit in a motor that is not pure stock or has many aftermarket modifications. My question is intended to learn your point and not argumentative. I understand its place in a stock motor and agree it is useful in that area. As most Cobras have aftermarket camshafts with the typical larger cfm potential carb with a fat primary and fatter secondary systems with enlarged cc acccelerator pumps not to mention the aggressive driving habits of myself and many of the brotherhood are in the stereotypical majority.
Locking the plate down stabalizes timming in high RPM runs and removes another variable for faults in a pure performance driven mindset. I do not have any vac. adv. system on my toy. I must also come clean in the fact I removed all the items mentioned above to install the Holley 4DI Pro-jection system and am using the variable timing programs (but electronic) with all the goodies (MAP, TPS, closed loop 02 sensor, IAC and more) I have written all my own maps and compensation charts because none of the stock stuff worked with my Big cam and 542 cubic inches at 13 + comp ratioon gas. Not even mention the modifications to the valve body and special lock up converter in the Automatic O/D tranny