There are two or three different Orings to choose from. Most trucks have an indention where the Oring goes, so it needs to thicker Oring. Some of the car Orings will not seal tight enough. When I did my swap, I had low pressure at idle and had to swap out for the proper Oring because the dealer sold me the wrong one

 

You're right, there are a few different o-rings. Do you happen to remember what color your "good" oring was? I got a full felpro gasket set, and chose the ring that most closely matched the original. There was a fair amount of resistance putting it on. I also insured it had a proper seal when attaching the pickup. Knowing what I know now, I feel pretty confident that the issue wasn't the o-ring, however I'll revisit when I'm reassembling. I still have the original to compare to.

My theory is that with the cam bearing, as loose as it was, allowed oil to flood out somewhat unrestricted. Without this restriction, at lower RPM's I had low pressure. As the flow increased with RPM I was attaining much higher pressure due to increased resistance.

I measured out the crank today, and got a second opinion on the surface finish. Luckily it's still serviceable. I ordered a full set of standard bearings that should be here tomorrow. Hopefully within a few days I'll know the results.

 

Anyone else think I should just run it?


I do have a question in regards to driving in the cam bearings. I realize there are different bearing sizes for each bore, however does it matter the direction that they're driven in? I always thought there was, however the most recent info I'm looking at says otherwise.

 

Hey guys just came across this thread, having identical issues. I replaced my oil pump and sending unit oil PSI reads 6-10 tops, interested I'm what were the causes in this case? Thinking my rod bearing may be my problem!

 

Pickup tube o-ring is most common culprit on oil pump jobs. I use double rings on my jobs, pretty much eliminates seating issues.

PS: I made slightly better pressure at idle with double rings rather than GM's square ring

 

happen to have any photos of the “double rings“ you used?


...and that BRP pickup girdle looks pretty interesting...

 

The BRP girdle is reported to have fitment issues on the truck style pick-up tubes or at least the ones that people have reported trying to add it to, due to the flange having an external tack weld that interferes with the girdle. It could quite likely be adjusted to fit, however in all likelihood it may not be just a bolt-on.

 

ah yeah, I looked a bit more into it....
I took a glance, and both of the truck pickup tubes I have are actually NOT welded at the flange. The mounting flange is actualy completely loose on the tube, but held on from slipping all the way off by a small metal “T“ piece that is like a place holder to just keep the tube from spinning too far...
I really have no idea why only the truck pickup tubes were done like this and not welded like others!??

I thought of maybe grinding the metal “T“ piece off, then just tacking the flange in place... but not sure if I'll go through the trouble right now.