Eliminating 17" split rims by boring out P30 rims

[Real Wrought]

What's the best way to eliminate split rims? 

The 17" bias tires have got to go!  What's the cheapest/easiest way to get it done?

I have a 7-wheel set of 8R19.5 tires (zero miles) that I just separated from rims off a 1985 Chevy P30 motorhome with 10x7.25 bolt pattern.  This looks feasible to machine 5 holes in the new rims that will bolt on the OEM hubs. The center bore has to be 5.75" as opposed to the 5.25 center bore on the rims off the P30.  Question- Who has done this successfully and can you tell me about it?  I'm bumping into resistance at machine shops who are reluctant to cut on the rims. 

[Oz]

Yeah, they're going to be reluctant for obvious reasons.

It's more than just boring out holes.
What about offset?
Brake clearance?

[Real Wrought]

A few years ago it was this forum they gave me the idea. Someone on this firm had said they had done it successfully before. I would love to find those old posts

[Oz]

Easy to find.

Entered:  17 to 19.5

In the upper right search box and selected "Google" from the drop down.

Read this, skip over the hijacking off to torque questions.

https://www.classicwinnebagos.com/forum/index.php?topic=14593.msg89852#msg89852