Cab Mount Bolts for Body lift

[mclairmo]

I am lifting my 68 C10 just one inch with one inch body lift blocks. I now need longer cab mount bolts but nobody seems to make them. I need 9/16 x 7" (or a little longer) and 7/16 x 6.5" (or a little longer). Does anyone know who might carry hex head bolts this long? I may end up having to call the body lift kit manufacturers and beg them to sell me some of their bolts since I am sure they must sell very long bolts like this as part of their kits.