340 valvetrain help
sounds like low oil pressure... goes away after 2500 rpm
probably a lot of miles on that engine.
but, maybe if you are lucky it's not that. if they are roller rockers, i'm assuming they are adjustables. if that's the case you will want to have some adjust the valve lash if they are solid lifters, or set preload if it's hydraulics.
if it's knicky knockin with hydraulics maybe the car has just been sitting too much.
but like others said, we need more info.