Does anyone have specific info on measuring piston protrusion?

I'm trying to figure out if a 603.971 has a rod problem. The #1 piston seems to sit at an angle relative to the other pistons. The piston protrudes seemingly normally on the intake side but much less so the exhaust side.

Should I set a level across the piston and measure protrusion at several points? If so should all points be within the single spec?

Which way does a 3.5 rod typically bend when it collapses?

Does any protrusion less than spec indicate a bent rod?

Thanks,
Sixto
93 300SD