This might be a dumb question, but here goes:

I know that in order to upgrade my C5 OS (359), I need to flash it with a 2001+ system, with all my current OS tables copied over. But does it matter which year I use? I noticed on Holden Crazy that there were several different OS's used from year-to-year. Also, I noticed that '04 Vettes use a 1 MB PCM, while all the others use a 512K.

Is there a preferred system, and which one might that be?

Thanks in advance!
Brent