IGN. use the "vac gauge method" to set initial then w that figure in hand shorten the slots to get 35 total then play w the springs & w them picked out set the vac adv (if used). More on the above later, I need to get to work, boss likes it when I show up on time. W the initial set if it still cranks labored, wire in a toggle sw for the ECU & w it off start cranking it w the key then close the sw. EDIT I'd dial in each subsystem of the dist in order then the carb and later (or right now) adv the cam 4 deg (recheck intake VP clearance if you think it's anyway near ~.125) then you'll need to go thru the dist again as the increased cyl psi will change your timing requirements then the carb again so yes might be for the better to adv it now which'll make the long block as good as it can get (as is)