Tuning my Slanty

Gents!
I am attempting to tune my Leaning Tower of Power and need advice. It was tuned by the PO and I have never fooled around with it, but my spidey senses are telling me she's not quite right and needs tuning.

Specs:
-225 slant with unknown cam (it's obviously not stock and pretty hot from what it sounds like-see vid)
-Edelbrock 1403 500cfm carb
-Offy intake
-Clifford headers into dual tailpipes
-new black Mopar ignition box from Ray (halifaxhops)
-new ngk ZFR5N gapped at at .030...

Tuning my Slanty
Author: MarPar