I my self would/have removed the sandwich heat exchanger ( modine I think it's called )
I also don't run water through the turbo ( but so do require it )

As for a spacer , if you need one then you need one
Just make sure it has no sharp edges for the oil to pass over .


How have you got on with the rad in the boot as my rad is in the boot of
My 3dr sierra

Cheers