396 bbc timing help

[fdbdw]

Hi all, I could use some help. 396 Mark IV BBC, mild cam. New cam, carb, dizzy, manifold & mid length headers. Im in the process of timing and tuning and I’m having trouble finding consistent timing numbers. In my research I’ve found everything from initial 4 degrees to 20 and everything in between and all in at widely variable rpms and degrees. Does anyone have solid numbers I can shoot for.
The other variable is 6,500 feet. In the past I’ve added 2 degrees per 1500’. Any added info on elevation would be great also. Today I’m going to verify TDC then start tuning n timing.
Thank you