Yet more questions, does anybody know what standard vauxhall XE 16v valve guides are made from??

I see that std ones are £30 a set and bronze are £200, but the std ones look a bit like bronze so what am I missing out on here!??

It may be the types of bronze:

Aluminium Bronze

Phosphor Bronze

Phosphor bronze is probably better in a self lubricating type of way.

The expensive ones are of a material tradename "Colsibro", is this a phosphor bronze?

COLSIBRO is a Copper Nickel Silicon alloy.

http://www.columbiametals.co.uk/coppernickelsilicons.htm

not sure on original guides, thought they were just a cheap material, can be brittle and crack when head problems occur, bronze ones are better and what we replace standard ones with on a race engine. there'as a guy on ebay who sells them for 160quid set, search on curly987 as username..

Ned.