I have been wondering what appears to be a rear main seal leak on my engine. Was thinking if it was the pump sucking the oil out? I never had a rear main seal leak ever!!

One of the great things about a vac pump is the engine doesn't leak any oil, when running. I get a drop or 2 after I turn it off now.

I know what your saying, i saw the filter they had that collapsed, didnt have a scratch on the paint till I put a tool to it to get it off, my reasoning is same, 50 to 100 psi inside, idk what sucks a pressurized filter enough to collapse it

I just googled it and found a reasonable article on what can collapse a oil filter:

https://knowhow.napaonline.com/what-...lter-collapse/

I wish you lived closer , trying to figure out how to create a low oil pressure safety into the tune , configure a custom 12v triggerd out map and rpm based output to trigger his shifter relay and finish developing his nitrous stages (cant figure out how to assign a pin to output to define it), set targets real low, rev it on dyno once to see them send out their signal then I can tear it off so I can get next motor on. The other jason you met who helped us with your holley is coming over hopefully!

The circular steel thin wall is great in tension (pressure). Terrible in compression (vacuum)

The only way the "Outside" of the filter can could be crushed inwards is if they ran the oil pump dry at high sump vacuum. Leaking pump pickup tube or pickup was not submerged - either of those would do it.
That would also explain bearings into the copper.

Could also explain the collapsed piston skirts. Wonder if someone got in a rush and forgot to put oil in. Or they flushed the motor between pulls with ice water and forgot to put water back in the cooling system.

Hard to know, they ran a carb with jet extensions in the FRONT and didnt know better, they revved engine '8200" even though the 280/800 lift roller cam is done by 7000, they set motor on pan. I built them 4 th-400s for there 4 trucks, 2 were for low hp 500-700 range so they didnt get ultrabells or aftermarket cases. They already brought one back with the bellhousing broke and asked if I missed that when I was rebuilding it as they say they never bolted it on a engine , LMFAO, there was a huge gouge in dowel hole where they rammed it on not lined up so ANYTHING is possible! I sent owner a picture of a titanium retainer in my lathe that I was doing a tiny cut on inner step, his answer back was "those new lifters look really nice"

wow,,thats almost like talking to cfm.

Yup.