Max lift with stock valve length?
stock valves? I wouldnt put more than 280-300 lbs on them. Close to .600 lift max. It's not about lift as it is pressure theyll break at.
I haven't used a stock 2.02 in almost 30 yrs. Last I did it was with a purple.557.
Those valve faces were hammered when the heads came apart and I went mancini stainless '$150 dollar a set specials'.
Those lasted 2 builds. Still have them in a box somewhere. Stock valves are too soft , heavy..and will break...and if they dont.. they will hammer themselves and start to leak.