In my opinion, if you're not running efi than you're better off blueprinting a stock HEI, upgrading the coil and module, and dialing in your curve with a spring kit and, if needed, a mechanical advance stop. MSD's quality has not been the greatest lately. Stock HEI is more than adequate with the right mods.
I tend to agree....the GM 4 post modules.. not the very early ones which I doubt any around any more... are sort after for modded high rpm motor bikes, even the dodge guys like them...
We tend to right off 'factory' stuff to quick... mostly due to marketing propaganda of aftermarket companies whos prime interest is returns to shareholders.
Yeah if getting into dedicated track.. one goes to fixed timing, magnitos etc...often track and street dont cross for good reasons.
And as suggested above, regardless of type of dizzy, it comes back the right timing at a given load at a given rpms right thru the rpm range... ideally within 1 deg...max 2 degs
Also The HEI was introduced not as a 'upgrade' but because Government pressures on emissions and economy... which meant introduction of EGR, for leaner burns... lean burn has more advance therefore EGR curves have a lot of Vaccuum advance and less cent....Non EGR as most of us have requires modding of the curves
Also, and think this maybe a legislation thing... dizzies off the shelf these days are set up for EGR.
Modding is not difficult be it a Factory HEI or MSD whatever.....detailed how tos and walk thrus in many older threads.
Big body HEIs often have issues with room next to the firewall... It the fan is not too close to the bottom of the shroud, then the higher trans mount option just sorts this out.....thu every 5 yrs or so u may have to replace the rear HT boot on the back of the dizzy cap