There are many ways to get to a 5 on 4-1/2 bolt pattern. If you are planning to go to front discs the 73 up front disc swap is probably the most common and gets you to 4-1/2 circle. Then you would need to redrill your rear axles or far better , find an 8-3/4 rear end and put in some 5 on 4-1/2 axles or get a later 8-1/4 with 4-1/2 axles in it. Many other options exist so you might want to do some research before buying wheels that you end up wanting to change.
