There is no straightforward way as the bolt patterns clash between 4 and 5 stud patterns what ever way you try

I have a set of 4x4 -4 stud hubs which are currently with a machine shop being converted to BMW 5 stub fitment so that I can fit a set of BBS split rims - this is being done as a favor to me and might still not happen if the machinists are not happy with the end result.

I sat with an engineer and the only way we could come up with was to cut a thread on the centre of the hub where the disc and wheel locate then spin on a seperate machined hub with a 5 bolt pattern which as a result also fattens out the centre to suit the larger hub centre that BMW use to make them hub centric with the BMW wheel

Welding was a no no due to potential distortion and disimilar metals ( the hubs are cast) - It could be done but I didnt want to take the risk

The new hub will then also be held to the old hub with grub screws set at a lower alternate 5 hole pcd pattern

Difficult to describe so here is a pic



A reverse thread will be used on one axle side so that as the car goes forward the hubs do not try to undo themselves - a bit like Old jag spinners

I am then using e36 M3 front discs and Brembo calipers from an 850

Granadas came with a 5 hole 110 pcd fitment and these hubs will fit Sierras but again few wheels come in this pattern and these holes still clash with the 5 hole 120 pcd BMW pattern so adapters are difficult to fabricate

These are the wheels I want to use



The machinists could have fabricated a new set of hubs but reproducing the inner splines would be very expensive