63-5 used very different brackets. When they stared using Saginaw steering boxes (mounted at just behind the front crossmember) they had to redesign the winch bumper.
1975 Chevy K20 8400lb GVW Camper Special
1971 Gladiator J2000 Platform-Stake Dump 350/T18
1970 Gladiator J3000 3407Z Camper Truck 350/T18
1968 Wagoneer Custom 327/TH400
1963 Gladiator J300 Townside 350/TH400