i have a 65gmc i have restored and it did not have a rear bumper when i got it. so i bought brackets off 65chevy truck and found out they will not work on gmc because the gmc has rear leaf and the chevy has rear coils and the ricets holding the rear leafs on are in way. should i modify these or do they make one for gmc. i am putting chrome bumper on rear. thanks for any help.