I heard that I can stack it with putting a PGM axle and regulary stacks. Is it true? Are there any other ways?

That will be your easiest way of doing it. One thing to think about, some of the PGM guts can introduce vibe and wobble to the Project 2. I have used two separate sets of PGM guts on my Project 2. One played dead smooth, the other vibed like crazy.

Thanks!

i put pgm2 stacks on my project 2 and it worked great till i tryed to take them out............................... it was stuch and a had to break the axel and hubstalk