5.9 worth looking at ?????????? from local craigslist

If you do the Keg mod's, replace the cam, springs and timing set, match the ports on the heads and intake to the gaskets, reseal the entire motor, throw a set of Summit headers on it, and get the ECM reflashed with an SCT Tuner; you'll have a solid 12 second A-Body. I did this exact thing on mine, but it ended up having a bad ring pack on #1 with only 90 psi cranking compression. It was still a fast car. I later rebuilt it to 408".

I believe this is a roller cam throttle body injected LA engine or at least that is implied by OP's description of early 90's W series truck, Magnums only came in Ram series trucks, not W series. If it is a TB roller LA, the kegger mods, heads and pcm f;ash dont apply here.