sure you can, worked for me. Not sure what you mean by longer spring perches. Do you want more than 1" of relocation? I would think axle wrap might become more and more of a problem the further you move the spring mount from the axles center... but I'll let suspension gurus speak to that. I'll have pretty close to 90 degree approach / departure angles on my rig with 56s front and rear... don't need much more axle relocation than that. 
j
j
...i'll be running 52/63s...so i think the rear 63s will provide enough axle relocation...it's just the front that i have to worry about...i'll be running 44s with a 52" swap...i'm going to move the shackle location forward, don't know if that'll move the axle forward, but i will be doing the redrilling of the spring perch...hopefully i can keep the tires out of my firewall 
