340 lifter noise

any ideas,ive been trying to figure this out since about xmas,i put in new headgaskets on my 68 340 .i got the felpro 8553 ones.after starting it up it has terrible lifter noise ticking.the rockers seemed loose so i bought a pushrod checker and it said about 7.53 so i found some 7.550 and put them in and it still sounded bad.so i bought some of the mopar .024 head gaskets with the stock pushrods and finally got it started tonight and it seems worse but now the rockers all seem tight .what else can make the lifter noise? they never got removed from the bores when it was apart the valves all open and close but ive about had it.did something happen by sitting for a few months ,i see oil on the rocker shafts ,the notch is down and front on driver side and rear and down on pass side.there is 60 psi on my gauge .this engine was quiet until i pulled the heads off.
thks for any help scott