Gav, it runs ancient k-jet mech fuel system and the WUR is abbreviation for warm up regulator (which is vacumn controlled)

Basically, on the back of the WUR there's a brass globe, drill thru it and there's an adjusting screw in there - what Stealth racing ( VW tuners Southam, Warks) do is adjust the control pressure so it allows more fuel delivery under load as the mk2 16v commonly ran lean flat out.

It's basically something you have to do to stop pinking when you fit a 2 litre block on these cars along with raising the system pressure.

Exhaust cam mod - It's a KR exhaust cam with the end cut off used as inlet cam, with a modified chainwheel to get the inter cam timing right ( the inlet cam is chain driven inside the cam cover from the ex cam which is belt driven )

Can't think exactly what the duration is, but from memory the ex cam has 10.2 mm lift rather than 9.6 for the normal KR cams.

I bought mine from a mate that had it done properly at Stealth but plenty of people 'have a go' at doing it.

On mine, the mid range is not as good as with KR cams, but it does rev further.