Pop pop on exhaust side

I agree that 18* degrees is not too high.
The point is that to get the idlespeed DOWN
with that much timing,
is gonna take shutting the throttles. And then the transfers get shut down,
and then the mixture screws get cranked open, and then the instant you step on the pedal, the entire low speed circuit goes rich;
and there is no good reason mess your carburation up like this , NONE.

That cam will idle at 5 measely degrees, or at 25. that is not the point!
the point is how easy this problem is to fix. That engine could be popless in the time it takes to swap out those plugs, and reset the T-slot sync.
If only the plugs are swapped, and no other changes, it will just start all over again.
If the carb is synced up, and those plugs left in there, then the car will need to go for a clean out run, to get the plugs to clean off, and if it's not done right, they'll just glaze up, overheat and maybe slough off insulator material, which can destroy the rings or the entire engine.
So I mean, how about you guys consider the big picture, that there is only one reason to run 18*, and is that so you guys can have something to flap your gums about.