Thanks for the reply's 
So the main message is avoid Highflowheads
And yes it is a shame to be honest Jonny. I like to think that pride would be taken when preparing a engine.
I will try a local companies.... but as Volcane said I would like somewhere that would run flow bench testing, pay attention to port shaping and the different specifications of diesels.
I have searched online for specialist diesel builders I cannot seem to find much, but there's a fair few in America. Shame it would cost a bomb to send anything there
That being said though this company does look very well set up... http://www.hurleyengines.co.uk/engine-machine-shop.html

So the main message is avoid Highflowheads

And yes it is a shame to be honest Jonny. I like to think that pride would be taken when preparing a engine.
I will try a local companies.... but as Volcane said I would like somewhere that would run flow bench testing, pay attention to port shaping and the different specifications of diesels.
I have searched online for specialist diesel builders I cannot seem to find much, but there's a fair few in America. Shame it would cost a bomb to send anything there

That being said though this company does look very well set up... http://www.hurleyengines.co.uk/engine-machine-shop.html