Stop in for a cup of coffee

So when I was driving the duster Saturday night to a school dance my dad, someone's pissed off mom, and one of my teachers said it was throwing flames and sparks. out of both pipes. It spit flames with the manifolds before but they were small and only out the drivers side bank, so I did not have high hopes it would do it with longer tubes.
but DAMN I was wrong!

When the throttles close.

Air at 14.7 psi pushes its way up the exhaust pipe. Hot leftover HC ignite with the input of O2.

it's at 12 degrees initial, and 35 all in
So that's 12 degrees at 600 rpm and 35 at 4000 rpm?
Or is 12 degrees at 1000 rpm and 35 degrees at 2000 rpm?
:poke: