lowering a 63 stepside

[evanmetal]

Looking to lower a 63 stepside long bed. It's got the 12 bolt in it and that seems pretty close to the fenders as is. And I'd like to go 5 lug. I've herd 73-87 but those are an inch longer? I'd like to stay away from shortening a 9 inch as its a budget build. Am I stuck with back spaces wheel s? I plan on bagging the rear. It's going to be a bike hauler so I need to get it as low to the ground as I can but still be able to haul 2 bikes or so. anyone got any advice?