[ultimateirving]

boost leak like killer said, and/or spark issue, whether ur plugs are gapped too much or ur coilpacks are jacked.. also what is the purpose of the safc 2? are u running a different maf/injectors/turbo/ what?

for a stock sr you wont need that, shoot most everyone says not to use them because they really can mess things up.
with a stock sr the right plugs are bkr(e)6 i believe gapped to like .028, use the copper if u can.

hope that helps, let us know more of what you have done

EDIT : posted this kinda late, after all the replies, and after reading more, i really think either u have a boost leak, or ur spark gap is messed up. and get rid of the safc with stock sr.
i ran mine with t28 on the 370cc's up to 12 psi for about a year and it didnt give me any trouble(i have a walbro fuel pump, which should be an early upgrade if you dont have 1). I havea wideband so i can watch my afrs too and it wasn't leaning out at all.