Thanks for input , i am familer with paperclip test etc and am quite happy with how she is running, i guess what i am asking is before i open up chip housing etc am i going to be able to identify a standard chip as oppose to a retro fit?
No your not, thats why I said earlier unless someone has bothered to label it, There not chip's as such but eproms (memory), so the actual eprom is the same type just programed differently, so its going to have the same chip name and type on it.
The oringinal eproms may have a ident label on them (normally silver foil type) but Ive seen originals that are blank.
People like Superchips and Courtenay put there own labels on and sometimes there piggy backed into another PCB with some addintional chips to prevent copyright.
Another giveaway could be if its a 'solder in' eprom (rather than push in), then chances are its original, unless someone has desoldered and soldered a different one, in which case you should be able to spot this.
Take the ECU apart and have a look.
there's a 'How to' here:
http://www.omegaowners.com/forum/YaBB.pl?num=1232908603