Well I have decided to pull the motor! Clean the metal out, change the oil pump. Should I go ahead a change the cam and rod bearings or just inspect them? What oil should I put back in it? Is there any other damage I should look for or any thing else I should do while I'm in there? This will be the first time I have pulled the motor out myself. Anything I need to know?

Odds are real high your need a complete rebuild. You have lost cam gears and lobes. The shavings have destroyed the bearings which is why you have low oil pressure. 20 psi on a cold engine is way too low.

So are you saying new rings too? Can I use regular 454 chev parts or what?

I would have the block boiled out. Rings & berrings are the cheapest parts in a engine. Upgrade to roller if you can afford it.

Boiled?

Hot tanked , starting at ground zero ! You will not find a quick and easy fix for this . Take your time and spend the money to do it right the first time. You will be a lot happier in the long run . Just my .02

Thanks for the help guys.

Update! I pulled the motor this weekend and yall were right! Metal was every where, I have to do a complete rebuild. All the bearings were shot and the new cam had a wiped lobe. So im taking all the way down boiling it, turning the crank, new main bearings, new rod bearings, new cam bearings, new rings, and new cam. Im planning on going with a roller cam setup and get rid of the dang flat tappet cam! I know i have to replace the lifters with the cam and a new timing chain gear. but is there any thing else i should do? Also with the new build, what oil should i run? p.s. im got a price on a gm roller cam. its just a stock cam. Im not sure if i have to replace my springs????

You'll probably need new pushrods for a rooler cam and lifters.

To go to a roller cam, you'll need the cam, lifters, and new springs. Figure around 1k bucks to convert to hyd roller. Flat tappets are ok, just need to use good oil, break in is CRUCIAL, and proper valve springs. Lots of flat tappet motors still out there running around.