MSD 6C and detonation

I've run a 6C for a very long time. Never had a spark problem.

BUT...I've always had detonation problems. I figured it was due to the crap gas of today and settled with running Trick or VP fuel. When running at the track, I didn't care. I always used some sort of real 'fuel'. I have the car on the street now more than the track..and the detonation issue is a problem.

My 6C quit. Car idling in the driveway...died. Crank, no start.

All MSD suggested tests pointed to the 6C. Wired in a new 4-pin stock box..started right up.

I had the engine tuned to something that sort'a kind'a worked with the 6C..no detonation unless I put my foot in it. That setup (4ºBTDC initial) with the stock box was a pig BUT I had no detonation whatsoever! I started bumping up the initial advance. I ended up with 10ºBTDC initial, 44º total (DC distributor with Mallory's YH mech advance set to 22º, and an 11º vacuum can), runs fine.

No detonation. None.

I don't understand.

I ran a question of 'Why?' by the MSD forum. Didn't get anywhere.

Anyone with a conjecture as to why an MSD box causes detonation where a stock style box does not?

General idea from my understanding is that a 'better' spark may well lead to LESS likelihood of detonation, not more...possibly less time for pocket gasses to heat up, pressurize into ignition.

This is a normally aspirated, carbureted engine. There is no rotor phase problem coming from an electrical retard with a full mechanical advance.

Any input would be appreciated.

Thanks!

Oh...I can provide all the specs on this engine, but that's not the point. The MSD detonated, and OEM style box does not..even with a considerably MORE advanced (initial AND total) tune. Yes, everything else the same: Fuel, gearing, carb setup...all the same.