FYI, I just tried to install a 165x42.5mm Fox DPS Performance and was able to get seat stay bridge to seat tube contact. I know for sure that this shock has a 2.5mm spacer and when measuring it at compressed length, it's just shy of 42mm travel, so it'd be 42.5mm with bottom out bumper compressed. I bought the frame used, I'm assuming it's one of the early ones. I also had a spare upper shock bolt laying around in case the old one was bent and causing a bit more deflection. It only had about 2-3mm clearance to the seat tube when putting my weight on the saddle with zero air pressure, but a few good hits on the saddle and I got them to touch. Good thing I was planning on getting the longer travel linkage anyway! Make sure you all check clearance when over stroking and consider that bottom out bumpers compress a lot on a big hit, and everything just generally deflects a bit more than you can make them with static body weight.