This processor will never work on an AmigaOne, or a Pegasos 1.
The bus protocol and physical design is completely different. You will need a different northbridge / system controller that knows how to talk to the IBM 970.
The IBM 970 processor has a 6.4GB/s interconnect (in fact, as the processor is meant to scale gluelessly up to 16 CPUs, it may have 4 of these interconnects on board) between the processor and the system controller (or another processor). This interconnect is probably very similar in concept to (if not the same as) the AMD HyperTransport interconnect as used on the Athlon 64/Opteron. That is, 16-bits in each direction, running at 800MHz¹ DDR (1.6 Gigatransfers per second).
As you can see, this would not be able to interface to a 64-bit bi-directional SDR parallel bus like the G3/G4 has. It is highly unlikely that a chip could be made to swap between the two types of signalling, and in any case, there would not be any real advantage if this was done.
¹ This may be 900MHz on the IBM 970 ... details are very sketchy
Edit: According to a PDF on IBM's website, the interconnect is 32-bits in each direction, and the processor package has around 570 pins, of which 161 are signal pins - hence there is only 1 of these interconnects on the processor.
http://www-3.ibm.com/chips/techlib/techlib.nsf/techdocs/A1387A29AC1C2AE087256C5200611780/$file/PPC970_MPF2002.pdf
(yes, that is a dollar sign in the middle of the URL!)
