I am at 321 SAE and have never had the valve covers off. To get in the 320 range without FI, cams, or ported heads, you will need a good cold air intake, longtube headers, a set of delete plates and a good tune. A set of underdrives won't hurt either. If you have a "good" car from the factory, that will get you there. Check out the classifides in a few days. I am getting ready to install a supercharger so some of my stuff is coming off.
2008 Vapor Silver GT, 5 Spd Manual
Brenspeed Stg 1 Edelbrock E Force, Liberty built 3650 trans
w/26 spline input shaft, N2MB WOT Box, GT 500 Fuel System, Kooks Long Tubes, Dynotech Drive Shaft, 3:73 Gears, Steeda UCA & LCAs, BMR LCA Relocation Brackets, Exedy Mach 500 clutch, Nitto Drag Radials
"RWHP - enough to get from 0-95mph in 7.61 seconds"