Alright my mind is burnt on this one

[Psyco Diver 69]

Ok, no more joking around, the "knock" noise is still there. From the last post I did about all this I checked more stuff out so heres what I know, feel free to ask me questions as I might leave out some details.:

The oil pressure when hot is at 20-25 and get to about 40-45 when above 2000 rpms

during the test drive I floored it I feel is not revving freely, almost like is struggling.

I took the oil cap off and it sounds like something is hitting again some thing think metaled, like the oil pan maybe.

When I'm under the car the sound is more defined and clearer at the back than the front of the motor.

After all my testing I checked the oil and its perfectly clean with no metal shavings

the last to times I had the intake off (Holley street dominator intake) I noticed the crack reappeared on the bottom on the exhaust crossover and the hole in the plenum dripped oil when I tipped the intake on its side.

Thats all that I can think of right now. Any ideas, cause I might just sell the damn thing