Ok, I have a forged LT1 355 that has 20,000 miles on it. When i changed the oil , i went with synthetic 5w-50 as opposed to 5w-30 because of the heat. About a thousand miles after, i noticed the oil pressure was very slow to come up. I mean it would stay at 0 and rise very very slowly until it would stop at 40psi. it stayed at 40 no matter the rpm. Now , it doesnt come up at all. stays at 0 and doesnt budge. It says "check guages".

I will verify with a mechanical, but doesnt this sound like a guage or sender problem?

 

How does it run? Sound any different? The easiest thing to check would be the sending unit (easy to damage when swapping an engine), but it sounds like the pickup may have fallen off in the oil pan. No pickup-no pressure. Does your pickup bolt on, is it welded, or just pressed in?

 

Bad sender... Wheew.

thanks