Is it possible to convert a 5 by 4 1/2 bolt pattern to 5 by 4 3/4 bolt pattern without using adapters?? Thanks for any thoughts.. Jimmy
Some certain mag/aluminum wheels have enough meat to machine them out to basically make them into unilugs, but it takes a competent machinist and the right lug nuts/washers to do it safely. They'd have to be some damn valuable/rare wheels in conjunction with some very difficult to replace/redrill hubs to be worth the effort. It is possible though. Steel wheels are a different story.
I have done it with aluminum wheels. Fairly easy on a vertical mill. I would not run a "unilug" wheel that is not hub-centric.
Hamber Rottenleonard makes drill guides for re-drilling your own patterns. I have a few. They work super-awesome, and come with the drill bits! http://www.rottenleonard.com/ He even made me a custom one!
I had my 55 Chevy axles drilled to accept Ford wheels, not a big deal, any machine shop with a Bridgeport can do it.