Ok guys, new to forums and this is my first post so my bad if I’m in the wrong one but this is what I got going on. I have a 2001 5.3 with about 200k that I built (working fine before I built it) I put a btr ls1 stage 3 Cam kit with trunion, push rods, springs, Melling high volume high pressure oil pump, I have a holley oil pan 302-3 with a baffle, after about 300 miles, I lost oil pressure from 60 psi at idle to 15 and from 80 to 40 psi when I’m on it. So I’m not sure if it’s the oil pump or something with the motor but I have a used LS1 block so I don’t know if I should take my chances and put my cam heads intake and accessories on that LS1 block. What do you guys think it could be? Should I just use the used ls1 Block? Could it be that the pump went bad? It’s just weird if the motor got hurt when it was good before and a little after it was built. I seen the difference about a week after getting it dyno. Let me know what y’all think, thanks

 

We can't tell you man, you'll have to tear it apart and check the rod, main, and cam bearings. Check the cam plate make sure it's tight. Check the barbell and galley plug. If you don't see anything there then yeah probably the pump.

If it were mine I would definitely go to a LS1 over a 5.3 if the LS1 is in good shape.

 

Drain the oil and cut the filter. What you find (or don't find) should give you an idea what happened...

 

When pulling the cam out I was only able to come out halfway and I heard a rattle noise and found out the cam bearing was out of its place and was damaged and scarred the cam a little bit. I had to tear the whole motor apart took the crank and pistons off and Dremel the cam bearing very carefully not to cut the cam 😬

 

Well at least now you know....

 

Good luck getting it back together!