car was misfiring quite a bit and as a consequence of a process of elimination i have replaced the ht leads, fitted a brand new dispack, new plugs, and new cam cover gaskets.
the passengers cam cover leaked again after the last change so i stripped it again and checked the cover itself. it is showing a slight bow in the plastic, what others might refer to as 'warped' i suppose. as i recently fitted metal cam covers from a vectra to my cavalier (see here:
http://www.migweb.co.uk/forums/projects-restorations/400026-ilovemyelite%92s-cavalier-v6-wip-pic-heavy.html) i had the original plastic ones kicking around in the shed, even if they were super-filthy. so i cleaned up the cavalier passengers side cam cover til it was as good as new and fitted that in place of the original omega cover (they're both the same part). it was definitely in better shape, so to speak.
all back together again and we're hunky dory; quite literally firing on all cylinders! wahey! happy motoring! and now i can keep the miles off of the cavalier as i was using that as the daily driver until i could cure the misfire on the omega!