We just got done doing the dyno run
http://www.randrperformance.com on Mark Mitchell's (LateGreatU2) LS-6 engine. Of the three LS-6's I have had built and dyno run in the last year, this one smoked them all. Running through a completely stock and restored carb from Eric at
http://vintagemusclecarparts.com , a restored distributor from Chris White, stock exhaust manifolds, stock intake and a cheap set of plug wires, the engine pulled 492 hp. I don't have the spec sheet yet so I am unsure what RPM the peak hp was at. Ron, who runs the dyno stated that through headers, a better (non OEM) ignition system, a 1" carb spacer and better plugs this engine should pull close to 525 to 540 hp. Keep in mind, this engine outside of an .060 overbore was built to stock specs using replacement OEM syle pistons, rods, cam, springs, valves, etc. The other two engnes were run through headers and both pulled around 470 if I recall correctly. I have a lot of faith in my engine builder (Total Engine, Bloomington, MN) and have used them for a long time as they have managed to bring a lot of my engines back from the dead over the years. Just thought I would share the run with you guys.