Hi all , when I accelerate the motor sounds rough and I get vibration through the floor pan , I am running 22" rims but I have had a go in another ft with the same size wheels and it is sweeter than mine . Gearbox performs as it should all changes are smooth and it locks up at55 with no slipping , the symptoms seem to get better when I boot it above 3k . All is fine when cruising at any constant speed it only seems to appear initially when booted . I am thinking either injectors or drivetrain . Motor is fine when stationary and revved.Thanks in advance for any help

There are lots of things it could be, have you started with basics and go the wheel balance checked, could be as simple as a weight missing.

Is it speed as in road speed that it changes or speed as in engine speed? that would help narrow down to wheels and tyres / suspension or engine / gearbox.

A rough running engine can cause vibrations. Driveline vibrations won't cause a rough engine.
Sounds like it's happening under high load conditions, high load = high boost. I would be checking for air leaks and turbo boost issues such as a stuck or inoperative wastegate.

Easy way to eliminate the gearbox is put it in Sport mode... it wont lock up or slip the TCC.... if your still getting the vibes then it will be engine related  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

Miggit , do you mean just sport mode or manual ?

there are 3 modes on the L322 gearbox, normal, then by moving the gear leaver left you get sport mode ( revs higher and opens the TCC ) and then by pushing the lever either forward or backward in sport mode you enter in to full manual mode So select drive and knock it to the left, but don't move it forwards or backwards  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!