i just recently rebuilt my engine an now it makes a horrible tap and my oil pressure fluxuates all the time. the only time it taps it when it gets to its operating tempature, but if i get it out on the road before it reaches that temp and keep it at a constant high rpm it wont start taping till i stop and raise the rpm's from idle. the oil pressure is screwed up all the time. when i bought the car it had a futral motorsports high lift cam futral push rods(stock length) and aftermarket valves when i blew the engine i put all stock back in it except for the heads that have those non stock valves. plesase help i have run out of ideas!!!!!!!!!!!!!

 

Did you check your bearing clearances before you assembled it? Sounds kinda like a spun rod/main? I'm no big engine builder, but for your oil pressure to fluctuate, seems like it might have something to do with that. Dunno though.

Chris