Sorry,
That was my big mouth that jinxed your engine
What year block do you have? '67 and up have provisions for hydraulic lifters which allow for pushrod/lifter oiling. "65 and '66 side oilers have no lifter galleys so unfortunaltely cannot take advantage of the newer designed forced oiling roller lifters.
Early blocks are splash feed only for the lifters, relegating you to a mechanical flat tappet, or as you found out, a solid roller tappet that needs periodic replacement.
Oil temps of 210 F to 220 F are perfect.
Also, the cause of the rocker shaft damage was the lifter. When the roller wheel and bearings went away the excessive valve lash caused the pushrod to pop out of the rocker arm seat and get wedged between the pushrod seat and the base of the rocker arm. When the cam lobe came around again and raised the pushrod... BANG!
I've seen it happen before and unfortunately I'll probabley see it happen again!
Rick, send me my 20 bucks
Sorry to hear about your explosion.
--Mike