on my 2000 blazer I have been having issues with the oil pressure being seriously low lately. I would have around 30 PSI at idle and around 40 at cruising speed when it was cold. Once the engine would warm up I would have 0 at idle (check Gauges light would flash on and off) and maybe 10 at cruising speed. I changed my oil pressure sensor, oil & filter, oil cooler lines & fittings. Now I have around 40 at idle, 60 at cruising speed when warm. Around 20 at cruising speed and 10 - 0 at idle. The longer I drive it the lower it gets. However, I don't hear any rattle or any unhappy engine sounds. So I am thinking that maybe the engine just has too much wear and needs to be replaced, but it only has about 145k. If that is the case, what years would fit my car? I was doing some basic window shopping online and I found some good deals on 96 - 98 engines. but once you get to 99 or higher it seems to get much more expensive. Any input would be helpful

 

I guess I should have also mentioned that I am looking for engines with 150k or less miles. I have found ones that are cheap but they have 200k+ on them. I am not going to pay to replace an engine with one that has super high miles on it.