.036 is definitely too tight. Sounds like there's no getting around getting the pressure plate milled. Personally I like to see .015 per clutch disc. in the front carrier so you need to get the pressure plate milled approx. .040" if you plan on using the .060 snap ring. .055-.060" if your wanting to use the .076 ring.. The high limit of .152 in the ATSG book is real loose for a performance build. The ATSG book is just a copy of the factory serv manual and factory specs vary greatly thus the reason for the wide range of tolerance. .046" is real good for the rear clutch. I usually run flat snap rings in any performance build. Like Zijmer said a loose converter will absorb shock so you don't usually feel the difference between a flat and wavy ring if you have a high stall converter. With a stock converter I'd use a wavy ring.
BTW: how much power are you running? I see in your tag line you say your engine is a 273. Is that correct? If so why are you fretting with installing 5 discs? 4 discs are plenty for anything short of a blown or nitrous injected 273 IMO
