Has anybody any good links for rover k-series engine tuning.

You need to search Dave Andrews. He is the absolute K series guru. Comprehensive website with lots of good info for DIY if that is your thing.

As above

Dave Andrews is the man on these engines

http://www.dvapower.co.uk/

Yes Dave Andrews, I hope he doesn't mind me saying that many years ago Mugen in Japan bought a head from him as his engines were beating theirs!