New ATI Radeon HD5770 on 2006 macpro

[innesireinar]

Just died the video card on my old 2006 mac pro (1,1). I've asked to an apple assistance for replacing this card and they asked me 400 euros (+tax), then I've opted for the new card ATI Radeon HD 5770 that it's not officially supported on my machine but by reading some comment about that it seems working fine. It costs less, about 250 euros (tax inc). The problem is that this card is higher than the original and it also takes the space of the first PCI slot where there was the core card. Now I have to put the core in the second slot and the accell (I have an HD2) in the third one. Just wondering if PT recognize them correctly in those slots.
Anyone?