figuring out advance timing

Same ol reguritations, with a few new insults.
I don't wonder at all about why a 'big cam' has different timing needs than a factory cam.
Both queries here were about mopar engines, one stroked, one not. The stroke effects the piston dwell at top and bottom so has some influence on the effect of the IVO and IVC. Other than that we can go from experience. I saw no reason to guide someone in the wrong direction as they begin to tune their car. If the owner/tuner follows the procedure I suggested there is less chance of unneccessary hard engagement. More so if its a nose in garage. Remember going into N before R on cold starts with torqueflite? Same idea. Why slam stuff if it can be avoided? Whether Champy's 800 rpm input ends up where it current is, or at or some other timing will depend on the results he gets. It may be 25* but experience points toward something in the 17 to 20* range is the better direction to explore first.

https://www.forabodiesonly.com/mopar/ams/distributor-starting-point-for-a-curve.182/