Dorick
I had Brad (his suspension tech actually) at HVCcycle.com in Nebraska do mine, they get your weight, back shock length, tire size, etc. what kind of riding, etc............the labor for the gold valves is not much.....like $125 or so...........I went the full route and got new fork tubes made at Franks Forks in Illinois pricey $390.........racetech springs ........gold valves........PVC spacers made and setup and assembled with 15w oil on their test bench, ready to install about $1100 with shipping. Cost a bit, have not ridden the bike yet, but on the ground they feel soooo much better than stock ones, I think the are going to be awesome.
I searched and searched, was hard to get a clear answer so I sent them off rather than butcher them up, maybe you could just send for the holes to be modded and the tops machined
THX Phil