I'm not sure how wild that cam is but I'd want it to idle lower. If bumping the initial gives more vacuum then it wants that much initial. I'd use the "vacuum gauge method" which is the initial that gives you max vacuum while lowering the idle speed back to the lowest it will function at then back off the timing till it loses 1" of vacuum & that's the initial it wants in drive with Ebrake on if auto or in neutral if a stick. right now I'd WOT nail it with 24 initial & see how that affects the bog. You can shorten the slots & since bumping the initial is giving you more vacuum you will have to shorten them anyhow once you get the initial finalized. Yes advancing the cam will give you more low end torque & is done first before the ignition timing. I'd take another compression test after you advance it & go with the setting that gives you the highest compression reading. After changing the cam timing you will need to readjust the dist timing. I'd set the initial then the slots to 35 (with vac adv capped) then springs then plug in/adj the vac adv. It definitely needs/wants more than 16 initial