Fuel pressure readings

This is the '94 RMS

Idle 35-36 PSI
Hit the throttle (quick snap) in park jumps to 45
Let off throttle drops down to 33 then back to 36

Hold throttle down in park 33-34 PSI then rises to 36 PSI once let off

Idle with no FPR vacuum 46 PSI
Unplugged FBR throttle snap 46 PSI
Plug FPR back in PSI drops to 36 again

KOEO PSI jumps to and stays at 44 PSI

I know the fuel filter is ooooooold and needs to be replaced, but can't say it'd clog to cause this issue.

Can't take a drive and watch gauge. Hose isn't long enough. Trying to borrow one...

Thoughts?

I had a car run on 20psi
thats not your problem IMO

It's not the problem, but it's a problem.

20psi doesn't sound like that car ran good at all if you're talking about an LT1.

Trying to remeber now if that was the operating or prime psi
I just remember saying after seeing it...wow...still running without issue
Think it was an intermittant start