I had some problems w/ burning up pushrod tips when the engine was first dynoed by Dwayne Porter. I already had the grooved shafts, so after putting the hurt to a few of 'em in a fairly short amount of time, we...
(a) added "connecting channels" from the rocker arms' main oil groove to the adjuster screw hole to make sure there was no obstruction to flow
(b) opended up the feed holes size (wasn't the same size from one rocker to the next w/ the particular brand I had at the time, oddly enough)
(c) added some anerobic sealant between the shafts, shims and rocker stands to try and reduce oil seepage from where they mounted on the heads
(d) ground small "flat spots" on the tips of the adjuster screws that were used at the time to make sure the screws weren't "point loading" in the bottom of the pushrod cups (later on switched to Smith Bros. adjuster screws which come that way)
(e) had the #4 cam journal grooved for full-time oiling to the rockers

I can't say exactly what mod was the true "fix", or if it was a combination of them. Regardless, haven't had any problems since doing these mods.