As far as filter media goes all racing line filters from Fram, Wix etc have a sybthetic filter media, a higher relief setting, less restriction, but also less filtering, around 25 microns.
As far as valve train noise, after I had bought my 77, I had the valve covers off to reset the valves, and while waiting to warm it up from cold, I noticed that the oil took a full five minutes, until warm, to come up to the rockers at all. It was completely dry up there.
It seemed like the oil was clean, but very thick, perhaps straight 50wt.
I changed it with the valve covers still off with 15w50 and then got oil with the engine cold immediately at startup.
Even with no oil up there for 5 minutes, there was still no noise.
Possibly your lifters are collapsing a little from increased spring pressures over stock combined with possibly less than perfect lifters and changing your clearance settings until pumped up. This does not necessarily mean the filter drainback is not working. It can happen within the lifter tolerances alone.
The ultimate cure, if you think necessary, is to use an oil accumulator for more reasons than just startup noise.
As far as valve train noise, after I had bought my 77, I had the valve covers off to reset the valves, and while waiting to warm it up from cold, I noticed that the oil took a full five minutes, until warm, to come up to the rockers at all. It was completely dry up there.
It seemed like the oil was clean, but very thick, perhaps straight 50wt.
I changed it with the valve covers still off with 15w50 and then got oil with the engine cold immediately at startup.
Even with no oil up there for 5 minutes, there was still no noise.
Possibly your lifters are collapsing a little from increased spring pressures over stock combined with possibly less than perfect lifters and changing your clearance settings until pumped up. This does not necessarily mean the filter drainback is not working. It can happen within the lifter tolerances alone.
The ultimate cure, if you think necessary, is to use an oil accumulator for more reasons than just startup noise.