I rode a BLT2 with a Pike 454 air set to 140 and it climbed fine, any thing shorter would help but it was not needed on my ride which included some really steep gruelling stuff. I did feel on the steep down hill more travel would have been nice, so my humble opinion would be to go for the 150rev as 120 would be fine for climbing if you needed it, I'm a fan of the FoxTalas 36 that gives you 100,130,160mm just a bit more weight.