Fresh 430 clatter!

[67RIV]

I just rebuilt the 430 in my Riv, with a Stage 2 cam. It ran fine for 1000 miles last summer! Everything is brand new with all quality parts, except that I was forced to put the old Rocker assemblies in, as my wife realized I was $900 over my engine budget. I intend to fix this eventually.
The problem is that I just started it a few weeks ago after the winter rest and it ran fine, but yesterday I started it up and it had the most obnoxious clatter/banging I have ever heard. My engine friend (who really built the motor as I watched) doesnt know what it may be, but said I should order the rocker assemblies, and pull the rocker covers and hope the problem is obviously up there.
Would a collaped lifter cause such a horrible racket? My carb is sickly and I think It leaks down after every use. Could that have affected the properties of the oil, and be causing the problem.
Oh, and by the way, the engine runs perfectly other than the noise, and the noise silences itself for a minute or two and then comes back. I am to young to have a clue at this point. . . .

Any ideas?
Thanks,
Kevin

 

[Syndicated]

An easy way to try and find out where the noise is coming from is to take a prybar and hold it to different parts of the engine while holding your ear to the other end, the noise will transmit up the prybar. You'd be suprised at what you can hear.

 

[rcull]

If you pull the rockers and don't see which is the problem do just as Syndicated suggests to each rocker as the engine is idleing and makeing the noise. I personally prefer a long screwdriver because it's easier on the ear...