Confused about which pcm to use after L32 swap into GT Grand Prix

Hope this isn't too confusing....I've swapped an L32 into a 02 GT Grand Prix. The L32 came from my 99 GTP which was written off recently- it had a 05 GTP tranny in it and used a 03 GTP pcm tuned by OverKill to run that combination. The 05 tranny was dying so I will be using the GT's stock tranny and I would like to keep the OverKill tune as well (ran great with this tune). Which pcm do I need to use- the 02GT or the 03GTP? I've been getting conflicting info - some say use the GT pcm and download the OK tune to it and others say to use the 03GTP/OK tuned pcm and load the GT tranny tune to it-- which is right?