Here's a fool-proof technique to build a Spark Table. It does not follow the GM model where spark is all over the place. It works much better. Agree with Fast355 that Vortec heads should max out at 28-30* advance. RPM at that advance subject to engine build, but generally 2800-3200.
https://www.thirdgen.org/forums/diy-...ml#post6301288