newish to me built 340 valiant feels sluggish. Timing?

(1) set initial with "vac gauge method" (2) then weld/file slots to get 35 total (initial+slots) (3) mix/match springs staying just under the pinging point at WOT up thru the gears on your hottest/driest day (4) plug in/adj the can & want to stay just under the pinging point in everyday driving under varying load/rpm levels on your hottest/driest day (CCW with a 3/32" allen wrench slows the curve/not the total). IN ORDER & can capped in (1) (2) & (3) unless you are tuning with manifold vacuum