Diablo with Murci wheels: centering rings needed or are the centerbores the same?

My 6.0 phone dials are 8.5 x 18 ET63 | 13 x 18 ET24.5 with a 5x120 bolt pattern

Random websites on the net says CB is 70.06 mm while murci centerbore is 72.6mm

That seems suspect. What is the actual centerbore on Diablo and Murci/LP640/LP670 wheels?

 

If so, I suspect something like this is needed?
https://a.co/d/2f51AoU

 

Pulled wheels and checked: they are both 70.0x mm

 

?? That seems like a bit of overkill. The Diablo uses M12 bolts about the same size as OEM BMW bolts of the time…12x1.5 tapered with a 25-27mm length.

Murci uses M14x1.5 bolts.

Just get M12 in the same size as the Murci bolt and your set? No need to retap the hub to a M14 size.

 

Would love to hear how @topcarbon approached it. I have been using late Murci wheels for several years with the OEM diablo 6.0 bolts.

What prompted this thread was I got curious what the offset differences between the 6.0 phone dials and LP670SV wheels.

While looking it up I noticed the odd centerbore listed for the Murci which made me wonder if centering rings were warranted (the difference listed from the diablo was roughly the same as that between a E38 and E39 BMW wheel and in that case rings are needed). I had never used rings and got curious.

This was 2016:

 

Might as well add, this is what I found so far:


Diablo Technical Wheel Data

6.0: 8.5 x 18 ET63 | 13 x 18 ET24.5 CB 70 (Confirmed)
Weight: ???? (I don't have unmounted wheels to check)

LP 670SV: 8.5 x 18 ET58 | 13 x 18 ET14.5 CB 70 (Confirmation pending)
Weight: 19.6 lb F | 27.7 lb R

 

Unfortunately nope. I am just checking/weighing what I have in my collection directly. The SV wheels are comically NLA now so its hard to find independent data.