Small block hei distributors

Had one in my D150. Worked well, was simple and easy, my only bone to pick? Every time I mashed the throttle and dumped the clutch the engine would rock the slightest amount and the vacuum advance part of the HEI would hit the firewall and advance the timing a hell of a lot. Me being a purist to my baby of a D150 I couldn't and wouldn't pound the firewall in or cut it to make room so I went to Pertronix. Now I did decide that for my dirt oval track car I will be using my old HEI because who cares about slicing a little out of that? My advice? Skip the HEI and just go to a Pertronix or another of your choice that is non-HEI.