Where the hell were you a couple of months ago!
My reasons for the quick change shaft are the same as you. I have the 3.17 for 93 tune (being done now) but would like to get a 2.85 for an E85 tune and swap pulleys fairly quickly. The last pulley change from the stock 3.35 to the Hellraiser 3.17 was a
dream. No more lifting the blower, 32 bolts, undoing the snout, attaching the Metco shaft holding tool, etc. Pop the hood, move the upper radiator hose, pop and swap the pulley, and presto more boost. 20minutes!