Noisy top ends.

[MB1033@aol.com]

I had read various "recipes" of lubricants to quieten 4000 lifters. I recently
bought an 87-1/2 CGT with a very noisy top end. I fitted new lifters , hoping
this would solve the problem. I was really cheesed off when it started to
clatter again within a few hours. 
Why is this ?  is the oil pump weak ? should I have bought "genuine" Audi
lifters at $30 each rather than the $10 ones I got? What can I do to shut it
up ?? Can I fit the older head with buckets and shims. Any advice appreciated