mk1 gearbox top end

hi, my mate has brought a 1.8 1989 mk1 karmen running on a peirburg, as soon he get on the motorway 5th gear  doing 50-60 mph the engine is screaming doing 4000 rpm.

any help would be good

Don't think any of the VW big block gearboxes were that low geared in 5th. The lowest geared would be an old 1.5 or 1.6 with 5 speeds - did they offer it as an option on the non-GTI???

sounds like the clutch could be slipping.  :dontknow:

Not sure what box an 89 Clipper 5 speed would have, but should be a lot lower revs than you mention - under 3000 rpm at 60mph. In fact, even close ratio 1.6 GTI 5 speed box does 60 mph at 3200rpm.
 
Cheers