VY SS rims. Factory or Fakes. Offset help

[ONROADYNO]

I just bought 4 x 18" x 8" rims that look like VY SS rims.

2 have about a 163mm back space and a part number, 92108750 (SFI 690kg)

The other 2 have a 155mm back space and cast on the back is a ZNL.. D349 (SFI 690kg)

What is the difference between theese rims please?

I am putting them on a VY ute with 235/40/18 tyres.

Which offset is better to use on the front/rear?

 

[lowandslow]

The ones with the 9210xxxx part number are genuine. The other 2 are not.

The fakes would probably be better suited to the front.

 

[ONROADYNO]

Thankyou L & S