EGR or Bearing?

I have a '95 Blazer. It has a loud knock to the engine.
The knock only starts after the engine has been running about 10 minutes and warms up. Along with it, the oil pressure drops and the temp goes up.
I read a few threads and it seems that it could be a bearing (needing engine replacement) or the preferred, EGR needing to be cleaned or replaced.
Any insight to this would be appreciated.

any codes? check engine light? how low does the oil pressure drop? how high does the temp go? done a tune up lately?

I haven't checked it for codes, but the check engine light does come on.
The OP drops to aroung 20 and the temp up to around 240.
as far as a tuneup, not yet. The wife just bought it in the present condition.
Need to keep her away from the bank. Anyway, after chewing her out, I decided to try to fix it. Deciding wether to scrap the engine or try to invest in an EGR.