there are subtle differences between the phase 1 and phase 2 zs's

have a lookie here...

http://www.zsoc.com/forum/showthread.php?t=190752

and here....

http://www.zsoc.com/forum/faq.php?fa...aq_differences

it doesnt really matter between the black top and silver top engine... black top is supposadly better, but if the silvertop has been looked after then they can last for a while.

check the rust on rear arches and more than likely they have been in a bump as you get the boy racers thrashing them!

lots of people on zsoc have put in the puma engine. quite a few have throttle bodies on them now and there is a turbo kit for the 1.6 on oc motorsport.

hope this helps!