Arrrgh Roco won't fit my RFX :(

So my 08" RFX is a bit of a fraken build - 650b wheels, Pike coil @ 5" ,7.5 x 1.75 RP23 for 5" in the rear as well. Geometry is trail freindly - BB 13.5" , 68* HA etc. I tried a Romic coil shock and forgot how much I was missing over an air shock. Purchased a Roco TST R in a 7.5 x 2.0 ( was going to limit the travel to 1.75" w/ custom nylon spacers) Anyways I thought a 7.875 x 2.25" Roco (5.625" collapsed) would fit an XL frame w/o the res. hitting the down tube. My Roco 7.5 x 1.75 would collapse to 5.75" , slightly longer than stock. Well the res. hits before the shock runs out of stroke Now I have a $$ shock that is useless :madman: Live n' learn I guess.