Juddering under reasonable load in 5th gear only?

[adigti?]

I have a 2002 awx pd130 5speed. It has an egr delete and the inlet manifold was burnt clean when fitted. It has also been remapped with a 162bhp blacksmoke map that has been used on another car with no problems. It has also just had a new LUK dmf, clutch and pressure plate. It is not showing any codes as was scanned by vagcom and vas and nothing came up.

So my issue is it accelerates through all gears apart from 5th. If I'm at around 1500 rpms and I accelerate I have a rev range of about 300 revs that it violently judders through and then clears. But it is inconvenient as 1500rpm is about 50mph which you want to be in 5th for but if you want to accelerate up to 60 you have to drop down the gearbox.

Can anyone shed any light on this?

Thanks