thanks for support, this morning i did my maths...
1) the new bushing overall length is 9.75mm
the swingarm width is 19.2mm
so the two bushes should be able to meet in the center as exposed and have a part left outside
2) the inside length of the old bushing is 39.5mm
the inside length of the new bushing is 44mm, but it's not supposed to be flushed
+the distance between the outside of the swingarm and the stopping lips inside (there's a lip to stop the bushings before they go too deep) is 48.5mm deep so the new bushings should not meet the stopping lips.
i don't see no reason here for trouble
3) the diameter of the new bushing is 26.99mm (digital reading)
the inside diameter of the swingarm tube is 26.91mm
considering the length of the bushing that needs to be pressed in, i think the problem comes from here, there's too much pression needed and the new bushing has deformed, and bloking the piece in...
conclusion
all the maths don't change reality, the bushing is bloked inside, the outside part left is 6.5mm and the old bushing outside measurement is 3.65mm, so i'd need about 3mm more and i can't do it.
i think my only option is to try to get the bushing out, but i'm pretty sure it'll be unsuable after that... if i can succeed...
bad sunday
Ben