I did some researching but I was not able to find a question to my answer.

This is for a 2001

At idle my fuel pressure gauges reads about 18.5. When I get into the throttle it decreases. at about 10 lbs of boost I am seeing 15.5 to 16. and at full boost of 20lbs I am seeing 13.5 to 14.

Is this normal?

I am used to my cars where the FP went up with boost. Is it not the same with my truck.

 

Perfectly normal.... and your readings are excellent. Anything above 10 psi at WOT is very safe.

RJ

 

Awesome. Glad to hear.

My dads 99 sport holds at 18 so I wasn't sure if mine was acting up or leaking.

 

what kind of fuel pump is your dad running and what kind are you running ?

 

Both are FASS. But I believe his is the type with the 2 filters on it. And mine is the single style.

 

You did not mention the FASS pumps in your first post. His will hold pressure better than yours but yours should not be dropping more than 2-4 psi.
Perhaps your factory fuel filter needs changing?

RJ