what the problem is, is the original xf mounts hit the side of the gearbox and the actual gearbox mounts up about 100mm further back

Do you mean where the crossmember bolts onto the body hits the gearbox?

yes the gearbox hits the original crossmember mount which is welded to the chassis of the van.. unlike other xd - xe's i have played around with before where there are two mounting positions on the cars for different gearboxes, there is only one on this xf van and it is about 100mm too forward

Wow I though it was only series II XF with only one mounting spot for gearbox (early XF had two mounting spots like XE), BTW those mounting holes have the opposite problem with a C4 gearbox, it is about 50mm to far back to bolt on a standard XE cross-member without modifying.

T5 gearbox mount for a XF might do the job as the gearbox mounts about that much further back, as for hitting, remove the gearbox box and persuade the metal with a big heavy hardened block of steel with a hickory or plastic handle.

cut out the protruding piece of old gearbox mounts from the xf and has done the trick just need to figure out some kind of mod to the btr mount now to make it secure