A month ago, i had my 1994 gsr with sri, hytech rep. header, greddy catback, no cat, exedy clutch and 9.5 lb flywheel. dyno'd. It put down 153hp and 109ft/lbs of torque. My afr's were mainly in the low 11's from 4000rpm till redline. So i decided to get a lc1 wideband kit, hooked it up, and street tuned my car since my ecu is chipped on crome with a gsr basemap already. My tuner leaned out my afr's mainly to high 12's and some spots were at like 13.2 at the leanest.

Now my question is, how lean can i get before its not safe for my engine no more? Also, about where is the reference point i should try to get my afr's to when tuning?

 

13.4 will be the pushing point for your motor.
Dont run any leaner then that, at WOT.