You can get them at Woodard spring in brockton MA,I think they can bend custom ones--also R.C. Truck Center in east bridgewater,they have buckets of U-bolts for various trucks(and they sell shackles,gas tanks,radiators,altenators,starters,brake and front end parts--their prices are very reasonable--they have body patch panels and fenders,doors,too)--last time I bought U-bolts there,they were only ten bucks each....hard to beat their prices-.....
-I got 50 bucks off a radiator at autozone for my brothers car when I told them R.C. had one for 110 bucks,and they wanted 150 at autozone,so the "zone" matched their price--R.C. had a Modine radiator,and autozone had a china crap one,so I should have bought it from R.C. in the first place--but it wasnt my car or money--so I wasnt too worried about it!....