I am interested to know the Brand and Weight of oil you use.

5W-X is too light...even for a fresh engine.

Use a 10w-x or even straight 30w and report back.

Cheers.

 

I see you put the new header gaskets in but are the headers hitting the oil pan and not seating on the head? Did you see any dark spots on the old gaskets? You can try to slide a feeler gauge from the bottom and see if it passes the gasket into the header. Or use a small mirror and put under the exhaust ports at the headers with the motor running to see if the mirror fogs up. Some headers hit the oil pan and don't seal 100% I like to use red RTV on mine to make sure they seal. Good luck

 

If it's a "bright" sound, it sounds like a rocker hitting the inside of the valve cover, if I'm correct on what I think you mean by "bright."

 

If theres not enough preload maybe you could try a set of lash caps for a little more load to rule that out.

 

I had a Comp Cam in my 383 that did the same thing. It drove me crazy. Called Comp, they told me I needed Adjustable rockers. I put a set of roller rockers on the motor, the noise was still there, but not as loud. called Comp back, they tell me to re-adjust the rockers. I do it and they still make noise. I call comp back again they then proceed to tell me that their lifters are noisy in the Xtreme energy cams. They would always bleed down. It pissed me off bad, and I don't think I will ever run a Comp cam again.
If you are running a Comp, I would suggest buying a complete set of new lifters from another company and start over.

 

Chris, I thought I had a Hughes lifter laying around, but couldn't find any. The oil oil groove on the lifter pictured looks a little narrower than the groove on some other hyd lifters.

 

I used two sets of comp lifters and now have the lunati cam and lifters in it. It has about 1K miles on it and still runs great but still has that annoying noise in it.

 

Had a similar experiene with a 360. Put i the XE268 and it had lifter clatter. Called Comp and went through the same thins as mentioned above with them. Bought new lifters to replace the really noisy ones. Still clattered. After that Comp told me to just live with the noise as it was inherant to the XE cams. Pulled that cam and put in a Lunati 268 and it was immediately quiet.

 

I know you said you de-glazed the lifter bores... Did you actually measure the ID of them them? Any larger than .906 and they may tick. Any stock type lifter should be quiet, conversly and anti-pump-up or variable duration lifter will be noisey. And they require different preloads. My money's on the bores being a little sloppy. Did I miss where you said what the oil pressure was?

 

It sounds like a preload problem I have heard of other magnum roller to flat tappet conversions that were noisy lifter and it came down to one of two things, preload as previously mentioned and or/the "correct lifter". The mopar and amc lifter are sold under the same part number but there is a difference between and the amc lifter is the one that worked best, I have also read that the comp cams kit to do the conversion has proven troublesome.

 

If it were me, I would swap out the lifters for some sealed powers and a set of adjustble rockers. It would help with the correct pre-load and lifter bleed down.

 

Make sure that oil plug is installed and is tight on the rear of the driver's side lifter oil gallery back there by the distributor.

 

He said he that he had 0.60"! Then he added shims.