Impactzone, are those the only 2 hogs you've shot with a bow?
Both of my hunting bows are 70lbs (73 & 74lbs), and my lightest arrows were 393grn with 100grn points, but I'm running 125grn points in everything these days. So those "short cut" shafts are 418grn with the 125's, and my "turkey arrows" which are long enough to give me about 1/2" shaft past my riser run about 445grns (I forget the exact number, not as much of a turkey hunter as deer hunter). I get 323fps out of my Bowtech with the 418grn arrows and 293fps with the 445's. 95 and 85ft.lbs. respectively.
I've been running Rage 125grn Chisel points for deer, but I suppose with that much armor and gristle, a 1pc or welded steel point would be a better choice. Maybe a NAP Bloodrunner? (I own 2 sets of Bloodrunners in 100 and 125grns.
I would assume that if I HIT the spine, my arrows would break it, as I've cut the spine and broken shoulders on deer even with the Rage's (100% FUBAR's the Rage's), but it'd be a matter of ensuring I cut the windpipe/arteries to kill quickly, AND severed the spine. Not knowing the anatomy in their neck well enough, I'm assuming that's not likely?