Youre still obd0, you need either a Pr4 or a Pm6. I ran my Ls off a Pm6 for almost a year no problems, ran a 9.6 in the 1/8 mile with that ecu so anyone that says a Pm6 wont run a LS can GTFO...no seriously the PM6 is mapped for a SOHC but you can tune the fuel a little with a fuel pressure regulator.
The LS runs like shat off a PR3, the head isnt built enough to rev past 7500rpm, itll float the valves and its pointless to do. Ive tried it, so you dont need to. If you build the Ls head, bigger valves, better springs and a camshaft then yeah you could take advantage of a higher redline but on a stock head it would be a waste..