Should I be feeling more power?

I would also make sure your throttle cable or rod is adjusted properly. Nothing worse than you thinking you’re at full throttle and you’re not.

It’s takes two people, but remove your aircleaner and have someone press the pedal to the floor. See if your butterflies are fully open or not.

Seems simple, but I have seen this a lot.
LOL......I bought a first gen Cummins truck like this. Seller dumped it on me thinking he had big $$$ problems.