I put new valve locks/keepers on mine when I did them. I always do that when I rebuild a set of heads. 20-30 bucks. Not all do this, it's up to you. I have seen results of a broken keeper. Not on a 7.3, but still.. I got some on ebay from a seller named falcon? I think.
On my heads I ended up with .045 shims iirc on each one. The actual installed height and seat pressure I don't remember for sure, and didn't write it down.
Darin 99 ranger 97F250 66 fairlanes
"TheBeast"1997F2504x4dually4.10's,160k,140VIDM,HPX,4-5"dp, S366 turbo w/wicked wheel, AFE, elec. fuel,rosewood stage ones,php hydra,arp studs, comp springs, smith brothers push rods, adrenaline hpop,riffraff res,melling lpop,180 tstat,6.0 fan and IC,trucool,coolant filter,scan gauge,lots of other gauges,racer x valve body and billet converter, upgraded trans, F550 leaf springs,SD dual tensioner upgrade, cold ac mod,OBA,38gal