Decided to install the diamond plate fenders. Had to remove the fifth wheel assembly to get access to the philips screws.
Installed them as far out as possible.
Should have put the fifth wheel back on after doing the supports. Would have been easier.
As I expected, with the V8 exhaust there is not enough room for the MAN battery box (the black bit) and air tanks.
I will put the servo kit from an 8x8 truck instead. This will also solve the hassle of having both diff lock servos in the fuel tank.