I have a 351C 4v thats in a street rod and mainly just a cruiser. It has stock 4v CC heads, Roller Rockers, Headers, and a comp 224/232 hydraulic roller cam. Mainly just a street engine. If I remember correctly it was assembled with the restricters in the mains and a standard volume pump. Its began to develope a tick in the passenger side valvetrain just like George is mentioning. Warm Oil pressure at idle is 25lbs off a dummy electric gauge. As soon you give the engine a little RPM they seem to quiet down or at least I can't hear them. I've adjusted the valves several times on that side and I can't get them to hush up. Any suggests on which way to go? It sounds like in my case the high volume pump might be the way to go. I don't plan on running it out of oil reving it to the moon, I just don't want the lifter noise.