Can't get rid of lean condition, part throttle low rpm

[shimniok]

EDIT: finally back at this after contaminating my tank, replacing it, installing correct injectors and throttle body kit. Story picks up again at post #36.

I've started tuning VE on my AMC 360 and am running into problems.

ECM is 7747, $42 mask bin based on ASDU. It's a stock motor with 3" exhaust. The truck weighs probably 5500# give or take and has 33" tires and 3.73:1 gears. I originally had a mini fuel pressure gauge showing between 14-15 psi.

I've started by tuning idle and working at exploring cells in lower rpms and progressively higher loads. I've been having a hard time getting the BLM numbers to indicate anything but lean. There's a definite power loss as I get into the throttle, sort of like a lean bog--but I'm in closed loop?

I thought I'd try increasing BPW a little at a time and see what would happen. While it has improved a little as BPW increases, the high load cells (let's say 50-70 kPA, 1200-2000 rpm range) in the history table continue to read lean -- 135-145 range. I'm at BPW of 175. VE1 table (I've added VE1/2) is maxing out in those areas, too.

Suspecting fuel pressure I swapped on a different (better?) gauge which reads 14.5 at idle.

PE is not disabled. Is that the reason for the wonky numbers? I don't see how because I can feel the lean and it gets better as I increase BPW.

I could swear I was running the appropriate-sized 5.7L injectors but will double check when I get a few minutes. I haven't checked fuel flow out of the pump.

What other things should I be looking at?

I've not touched spark advance. Is there any way that might come into play? Maybe that's where the power loss is coming from.

My catalytic converter is suspect. How likely is that to cause trouble? Some honeycomb chunks blew out the tailpipe. I like to troubleshoot by testing and trying the cheap stuff first, rather than throwing expensive parts at problems hoping the next one is the fix. :)