Hello new here. Thanks for giving me the opportunity to ask and learn. Ok so here we go. I have almost 400k on my truck. 5.3 2wd LMG engine. Last week I had cyl 4 lifter collapsed on me. I ordered a DOD delete and stage 2 truck cam from BTR. Came with new springs, valley cover, cam thrust plate, new head gaskets, timing cover, lifters, cam.. Disassembly was easy. Everything came off or out with no issues. This is my first ever can swap so I tried my best to remove the cam without major bumps and whatnot. Seemed to come out fairly easy. Once everything was removed, I did my best to clean whatever oil slide was on the heads and oil pan and timing cover. I also installed a new melling 295 hv pump with pickup tube. The red o ring was already on the pickup. I got everything put back together with no left over parts ( lol) and started right up but sounded horrible. It was like a diesel. I turned it off after about 15 seconds. The gauge on the dashread 0 for oil pressure. I have torn everything back down to make sure my o-ring is seated properly and I primed the oil pump put everything back together and still the same issue. A nasty ticking sound and no oil pressure. I think I suspect my cam bearings are going bad. Would this cause zero pressure? Any correct help will be greatly appreciated

 

Could even be a bad new pump. Sucks that you'd have to tear it down again but you could just slap your stock pump back in there.

 

I seen a cam bearing fall out of one when the cam was removed recently. That would def cause no oil pressure.