You could do what I did for my '86 GW.
Buy the drawtite 3 piece hitch for your vehicle (get one for a '86 GW if not listed for your vehicle)
Get 2 pieces of 6" angle iron cut to the same length as the original rails.
Discard the rails that come with the kit, cut and drill holes in the angle iron so the receiver hitch crossbar will bolt into them, drill and cut the angle iron to match your existing holes. Looks like a professional job when you are done.
I think I paid like $125 for the hitch and I got the angle iron free from a scrap pile.... I used 3/8" thick angle iron -- prolly overkill, but at zero cost and only slight added difficulty in cutting it, I figured it was good insurance.
I don't like the idea of a trailer potentially falling off or getting loose because my rails / hitch broke...
Hope this helps
Just my 2 Cents (Good grief!! Even my weedeater laughs at me now!! Silly gas prices!)
1986 Grand Wagoneer (225xxx)
1988 Comanche Pioneer (215xxx)