valve length.

Hey guys worken on a 70 383 hp & was wanting know what the maximum difference in the valve stems installed is. So other clown has been working on this before & using a stright edge across the stems.is .030! That sounds like too much to me for non adj rockers! All the intakes are a bit taller than the ex. valves .Some peopneed to nkt even bother worken on this stuff! Looks like my only way outta woodsis adjustable rockers & matching push rods? What do you think? Thanks.