XVs have odd sized valve stems and faces. I have the cutting heads and pilots necessary to give (920 and larger) 5 angle valves jobs. The rocker shafts are incredibly tight in the heads. I have the proper slide hammer. The valve springs and retainers are larger than practically all motorcycle valve spring compressors. I have one that works. The intake port is of smaller inside diameter than the rubber flange of a 40mm carb. I have a lot of carbide cutters.
I can enlarge the intake ports and broaden the exhausts. I can give elaborate 5 angle valve jobs. I can assemble the valve train: rockers you have bought; valves you have bought. If necessay, I can install the cams and bearings. The heads will work and you can avoid a lot of nit-picky work and potentially broken parts. It's not cheap: $450 exchange. I can work on your heads, or build some from inventory and swap you when they are done. I work slowly, so I can only build a pair every couple of days.
Keep in mind that you won't be getting a thousand dollar port-and-polish. For one thing there is very little room above the exhaust port. When learning I broke through to the exhaust spring base - oil everywhere. And secondly, I don't believe in intake ports smoother than about 240 grit. See here.
If you want rockers, valves, springs, and adjusters as part of this operation it runs $1325 You will likely have bought your springs as part of a cam set which drops this operation to $975
Please send your heads with rockers in place, the valves in, if possible, the studs and dowels out, and clean the grease off as well as you can. You may not get your original heads back unless you specify that that should be the case. Please: no broken fins or scratched gasket lands I don't send out heads or barrels from inventory that are obviously damaged and I expect the same for those coming in. You'll get back attractive, durable heads with internal hex driven intake and grade 12.9 exhaust studs.