Well, generally, over 7 or 8 pounds in my experience is no good on any stock motor.
Except the few Honda's I've boosted, with a good tune those can take some boost.
The EGT's you'll see will be phenominal, that poor 3.0 will probably just melt, pistons, valves, everything will take a huge hit.
I ran my 2.3 Turbo coupe on 8psi stock on 93 octane, could never get it to run right, finally I melted the number 1 piston, and exhaust valve, and welded the spark plug to the head, stupid me, I went and tore it down and rebuilt it, ran it on 14psi everyday, dogged the hell out of it, never gave me a problem.
I'm not thinking you'll be able to do much with the 3.slow stock.
Nick Conforti - 1987 Ranger XLT - 302 - Cam - Edel Intake - Edel 650 4 Barrel- GM HEI - AOD - D28 - 8.8"- Discs - 31 Spline - 3.73 - L/S - 30" - Sony Headunit - Kicker Components - 3 12" Audiobahn 1251T @ 35Hz - HFi1000.1D Mono Class D