Just my testimony here...take it as you like. I run 19-20 psi with 93 octane and NO alky. I DO have a RJC power plate, Duttneck SLIC, Walbro 340 pump w/ hotwire. I DO monitor my fuel pressure gauge, my boost gauge, and my Scanmaster. I also have an AXIS controller that I can add fuel if necessary. I'm definitely on the edge, but my car takes it with NO knock. As stated above.. I would not suggest running above 19 psi without higher octane, alky, or E85. As far as "acting up" I suggest that you gap your plugs tight... 24-28, as higher boost levels can blow out the flame, causing spit and sputter.
Get yourself a Scanmaster, and install your alky kit, and be prepared to service/replace the alky pump every 2 years.