also re: fueling i beleive the overboost kicks in at 10psi on those, so 9psi is your limit... (dunno if that means its safe upto 9psi tho)

also please note, DO NOT HIT THE REV LIMITER (if it even has one) as on the DOHC this is a FUEL cut and with your extra injector still firing this will get very messy very quickly!