[rritchey]

I agree with cobrabill, it is unusual for an aluminum-headed FE to want so much timing. I built a stroker 427 (454) just 3 weeks ago and ran it in on a dyno, it made best power at only 26 degrees. It was a mild engine, a smaller street hydraulic cam, Arias flat tops, Edelbrock heads and intake. I have also built higher performance 427's (600 HP range) that made peak power at not much more than 30 degrees. The new Edelbrock heads seem to reduce the total timing on every motor I have used them on, because if I had put factory heads on these motors they would have wanted closer to 40 degrees. I'm not sure what it is about them, but the aluminum heads don't need the timing advance. If you are running aluminum heads and have your timing set in the 40's you probably have something unusual going on and are not getting your full potential. Just some thoughts.....