[Steeveedee]

GM's engineers agonized over those details, believe me. Now, all bets are off, as the fuel and other emissions requirements are completely changed. If you have ready access to a dyno, and a nice parts guy who will let you experiment with a number of vacuum advance assemblies, you could probably end up with a nicely drivable truck that doesn't suffer from detonation from over advanced timing, yet has enough advance to provide optimum mileage. I can't steer you in any direction on this, as I am in the same boat myself. I use the highest octane local fuel when towing the trailer, but am not convinced that I'm not doing damage. I want to rebuild/replace the engine in my truck, and I'm going to have to do a lot of homework to get it right. The current setup seems to be pretty good, but the rebuild has close to 100k miles on it.