VDO Rev Counter Query

1996 Defender 300tdi 110 CSW

So, I recently had a new old engine fitted (it was a disco 300tdi) and since then the VDO rev counter (installed by the previous owner) has been reading high.

About 1200rpm on tick over, previously 8-900rpm and 4000rpm at 60mph, previously about 3000rpm.

Firstly; are these high? I think they are!

Secondly; can I "adjust" or calibrate the rev counter to bring it back down.

I've not had the instrument panel off to have a look as I wasn't sure if it might be something to do with the alternator.

Thanks in advance,

Mo

Will be down maybe to a different alternator (more poles) or alternator speed (size of pulley) or both. They are adjustable do a search.

Thanks, I should have searched first

Most of the VDO Rev counters I have seen have a switch between 4-8 cylinder engines and a screw to adjust the reading up and down. It should be on the back.

Thanks, I managed (after a great deal of googling) to find the instructions for calibrating. Just waiting for me £10 laser tacho!