This is where I’m at as well.
Without dyno data and/or track data it’s hard to say if the car/motor is actually under performing, or if your expectations for what you built were a little high.

I’ve had a few motors come into the shop where the owner thought they wanted “more” than what they had.
My first step is to dyno the motor as is(if it hasn’t been done previously), to see if it’s doing what it “should”.
Then after the rework, it gets dynoed again.