Seems rather low to me as well even with that 3.4 it's showing 14 or so PSI.
This dyno was done on about 15 psi and a worse tune... So not sure what the deal is there.
http://www.gppimp.com/photos/main.ph...serialNumber=1
Sorry for the horrible scan of that dyno sheet.... that run was 365 fwhp on a Mustang Dyno at Livernois. about 15 psi, 9.5:1 a/f ratio, and 12.5 degrees of timing. IIRC it was about 90 degrees out that day as well. not sure about the barometer.