Moser 60 and Wilwood 14"

[chicane]

This isnt really a "new" issue... in fact, it's rather common when using various manufacturers in any given build.

What I have observed with some of the newer hat's... and in specific to the newer offerings from various manufacturers... is that the hard coating/anno thickness is the most likely cause for the dimentional changes of the hole. There is no standardized coating thickness and at times when new parts are created or when you source 'other' companies for coating hard parts... it can go sometimes unnoticed. Next would be an insufficient chamfer for the portruding knurl shoulder of the fastner itself. With the available manufacturers for fastners... it falls under the same premise.

Since there is no real common diamention for this peticular (issue) process... as the variables are too great between manufacturers, pre-assembly becomes paramount, to address the unknown.

I believe the easiest solution, would be to simply ream the flange side of the hole. Machining isnt really necessary.