5.5 to 4.75 bolt pattern conversion
Is it 4.75 you want or 4.5 ? 4.5 is the common ford "car" pattern.....
Going from 5.5 down to 4.75 shouldn't be a problem. Pull your axles and take them to an auto parts store that does machine work. They should be able to do it for no more than about $80 for each axle.
If it's the 4.5" bolt pattern you want, then read the rear axle thread in the 48-60 truck forum that I told you about in your other query as it discusses how to pull your 5.5 pattern axles and replace them with 4.5 pattern axles.
Later,
To change your bolt pattern to the 4.5 you need axles, drums and backing plates. The thread I have referred you to explains which ones will work for your rear end. There are three different widths of drums available to you - the difference being the width of the brake shoes they use - 1.5, 1.75 and 2.0 as I recall. I seem to recall the difference in width is handled by different offset in the backing plates not through different widths of actual drums.
I don't want this to sound like an insult because it is not intended to be one - You seems to have limited mechanical experience.
Your main purpose here is to use wider wheels and tires without having them stick out of your wheel wells.
The simplest way to accomplish this is to order custom offset wheels from someone like Stockton as I just mentioned in the other thread you started.
Not necesarily cheap, but simple.
Otherwise, it is fairly simple to simply swap your entire rear end to one of the
alternatives mentioned in the 48-60 thread....one of the slightly narrower ones. But this requires some skill. You need to accurately measure how much narrower you can go from inside of backing plate to inside of backing plate without having the backing plates hit your box sides on full suspension compression. You need to calculate the offset for the wheels that you would put on this new rear end. You would have to likely cut of the spring perches and re-attach new ones to correctly line up with your stock springs. (This last bit is fairly simple but involves some grinding/cutting, setting pinion angle and welding)
Or the third alternative is the axle swap we talked about in the other thread. For this, you have to get the parts from a wrecking yard and take them to your mechanic to pull out your old axles and put in your new ones....
Later,




