checking pushrod length

[hillytim69]

I had both rocker arms come off on #1 cyl. Looks like intake valve stem is damaged and corresponding rocker arm has uneven wear mark. looks like one pushrod bent and rocker fell off and knocked the one next to it off as well. Funny thing is that I had previously robbed a rocker stud from this head so my cyl head guy gave me one from his spare parts bin. It is a different brand from the rest but still correct part. IDK if this is coincedence or could the stud be bent or somehow cause this problem? Also i am now trying to check pushrod length. I have 383 milled to zero deck height (says builder) ported World S/R heads with screw in studs, elgin 1.5 stamped steel long slot rockers, .480 lift single pattern cam, hydraulic lifters and stock length pushrods. I tried putting #6 at tdc and coloring stems with a sharpie then adjusting to zero lash plus 1/2 turn but am not getting a well defined line across the stem afterwards. it seems to rub most of the ink off. If anything there may be a faint line towards the header side of the stem which would indicate the need for shorter pushrods but I can't be sure. Am i doing this wrong. At a minimum now I need to pull the head to have valve with stem damage replaced. Any recommendations how to check this pushrod length? I've never had so many problems before with all the 350's i put together. Seems like 383 has lots of little things that need to be checked out and be just right. I think the pushrods were crane or summit with welded tips but otherwise cheap stock length ones. Should i be using pushrod guideplates? Thanks guys