Ok everyone who has been following the sega on my 300SD re:78 injector pump into in 80?

I got the car running today, took alot of cranking and a new starter (no there is no fusable links associated to the starting system) but it does run now.

Now heres the newest problem:

when at idle the oil preasure is showing #1 on the guage, and it goes up too #3 when revving. There is a loud um......banging.....clanging......almost like a rod knock, but I don't think it's that. At idle it's very pronounced and gets worse the more you rev it up, with a maximum redline of about 4000 rpm. When you take the aircleaner off it gets really loud, almost like there is a crazy guy inside the engine hitting the block with a hammer. When you put it in gear there is no power, but i can hear the turbo spool up, sounds like it's really trying to work, even when in park. After you hold the throttle to the floor for a couple of seconds, you can't let it off too fast as the engine will stall.

All the fuel filters have been changed, including the strainer in the tank, and it has fresh fuel in the tank.

I think I am getting closer but not sure which way to turn now?