Noise Issue

hey guys, been a while since i have been on here. Well i have a little issue here. I have an 87, I did a mass air conversion and a cam swap in january, i put a b303 in it, stock heads and rockers. All was well and car ran like it never has before . I was hanging out with some buddies and did a lil burn out, it reved to 5100 rpm, then started to misfire and making all kinds of noise from the lifters, had great oil pressure still. I replaced lifters again, running again and pretty good from what i can tell, now it has a freaking tapping noise from the passenger rear side of the valve cover, kinda sounds like a roller rocker that needs adjusted. heres the kicker, when you rev it to about 1500 the sound kinda sounds like it moves around from rear to front and so on in the valve cover. i have triple checked the rockers, lifters and push rods. Im just about to give up on it here soon if i cant figure it out, been ready to hold it wfo to see what lets go then starting over. Thanks guys