What is the best timing on a stock lt1?

 

how about stock timing

 

As the man said: stock timing - you can get your pcm reprogrammed to increase your spark advance - but, why? Our engines run a fairly high compression ratio - advancing engine timing could require higher octane fuel (higher than 91-93 octane you find at the local gas station) which requires you to purchase octane boost, or run racing fuel, or a mixture of aviation fuel and regular car fuel (all really expensive options) to avoid detonation. And there's no way you're going to run any real nitrous system with cranked up timing (that is, if you want the engine to last more than a few runs) In fact, you would probably want to detune about 4 degrees of timing or so to run even a hundred hp shot of nitrous if you want your engine to last any real amount of time. I would leave it alone and focus on more feasible upgrades - i.e. cai, headers and good exhaust, gears-4.10 for manual, 3.73 for auto. But, all this is really just my opinion.