Engine guys please help!

just read this about the casper cap I don't really know if could be your problem
Note that the new Casper's replacement cap is installed with the timing mark set at zero rather than 25 degs ATDC. It has an led in the top that comes on when the cam sensor is installed correctly, and, this greatly simplifies installation if the sensor has been removed, or, the original cap has failed from( Vortex IHADAV8)
New design provides a simple and accurate procedure to set the required 25 degree ATDC cam sensor signal. Has built-in LED which indicates an exact setting point. You simply rotate your engine to Top Dead Center and this cap does the rest. No need to index your crankshaft away from the timing mark! from (Casper)
Did you do a compression or leakdown test when the engine was together BEFORE the bearing issue? If not, the current ones only show what you have, not a meaningful comparison.
Compression and leakdown, if it is as even as yours is, has nothing to do with the unbalanced mixture issue you are currently experiencing. Let's assume for now that the long block, and cam timing are fine, and figure out what is causing the unbalanced fueling issue.
Since our normal, non high zoot engines have only one O2 sensor, it can only read the AVERAGE of what all of the 6 cylinders are doing.
What can affect this unbalance?
Individual injector filters
Crappy injector(s)
Restrictions (junk or corrosion) in the fuel rail.
Bad injector (leaking or under fueling)
Corrosion at the injector power plug(s).
High resistance or intermittent connection in injector individual wiring harness
Regulator diaphragm going bad, therefor changing/ fluctuating fuel pressure
Partially or intermittently plugged fuel return line (could be in tank, connection hose at the tank, or in pump/sending assy.
Fuel pump intermittent power wire or relay/ ground.
Bad/intermittent power or ground(s) in injector harness/plug in.
I would: connect a fuel pressure gauge at the test fitting on the rail. Is it consistent? Moves around?
Remove the fuel rail, blow it out, and put it in carb dip over nite or longer. Blow it out again.
Disconnect the return line, blow it out, (disconnect from tank) and or run a length of hose in a bucket and see if it has a steady return flow.
Have you replaced the fuel filter recently?
Blow out the fuel lines individually from tank to filter, and filter to regulator.
Read the pump voltage at the TANK while running or key on/engine off.
Rig up a "T" in the return line off of the fuel rail, pressure there should be minimal.
Any electrical intermittent to the pump or grounding, pressure or return line partial restrictions, or regulator/ filter intermittent restrictions will cause the computer to "chase its tail."
Start with the easy ones first.
Pack a lunch, and Excedrine, you're gonna need it!
Keep us posted.
The fuel pressure is being logged in powerlogger and has always behaved correctly but I replaced pump and wiring anyway since it was old. I have measured and tracked fuel pressure with boost via PL extensively last season while trying to find my "false knock" problem. The fuel rail was cleaned and blown out before the first build was assembled. No signs of a regulator problem or diaphragm issue or any intermittent voltage (also logged)...no unexpected pressure spikes or drops. Injector harness is new with the first motor build, it's a 40k mile car so generally wiring is in pretty good shape.
I will double check voltage at pump and put a gauge on the rail and verify we are still good, and I'lll swap the fuel filter as I haven't in a while. But seems these issues would show up more under load than at idle which is really only where I'm currently noticing over fueling issue. I also like the "blow out the lines" idea so I'll get going on this stuff. Thank you all...I'll get back when I have info. I have limited ability to work on the car so it takes me time. Thanks for your patience.
I would remove and clean EVERY ground on EVERYTHING under the hood. Some single wire apparent grounds do ground multiple things. Check engine ground braided straps. Also with the engine running (do this with it hot and cold), measure from the temp senders (3) bodys to the BATTERY negative and look for voltage drop. Then probe maf, tps, O2 sender (is it new?), at the SENDER side of the plug in, in some cases a straight (am I allowed to say that?) pin thru the insulation is needed.
Here in Arizona, we encounter corrosion on ground issues occasionally, so I am sure it is a problem elsewhere back East.
I have seen bad grounding on alternators too. Check at idle, then 2000 or so RPM from the case back to the battery - with headlites, A/C, and other electrical loads on.
All senders operate on voltage/grounds, the computer then reads all of this, garbage in equals garbage out.
The computer doesn't know if the resistance reading is from the temp sender itself, or temp sender plus bad ground to the manifold.
New alternators are dipped in shellac after cleaning and I had a customer come in with THREE new "bad" alternators he and a neighbor installed. I measured case to neg battery voltage, and it was 14+ volts!
I removed it, cleaned off the shellac from where the thru bolt went in, and wire brushed where it went on to the head and bracket, and all was fine.
P.S. the computer water temp sender in my car had enough Teflon tape on it to completely insulate it from the manifold!
If they do ground well to the manifold, is the manifold grounded well to the block?
Ya got a lot of checking to do!