2005 38 lightning low top speed.
 

Are you running the same props that came from the factory? (The ones indicated on the performance report) Are you sure the test report says 93? That sounds a little on the optimistic side, maybe 83 but not 93.

Factory top speed is with no gear, barely any fuel, one person, but you should be closer to it than you are indicating. Check for accuracy in your drive/trim setup and duplicate what the report says to get a baseline.

My 02 38' semistagger w/575's did 93 with Bravo 32's
I think 525's did 89
If you're full stagger it should be faster.
Props turn in? Should be
Drives toed in? 1/8" is good
Sharp skeg, no burs
Verify trim and tab indicators are correct.
Lacking RPM on one engine could be prop bigger and/or cupped more than other side. Or, that drive is not trimming out as much.
More RPM on one engine could be trimmed out further, prop that's smaller, and/or cavitating.
Make sure drives don't have slop from one to the other
Check base timing, fuel pressure.
Lay off the meatballs

Knew a guy that had a bone stock 525HP - 38 semi-stag with 5 blade hydros that ran low 90s in summer heat all day. You have something else going on.

Yea Anthony's old boat running hard (later owned Saddle Up Statement) ran the same. You have tired mills or hook or something else going on.

First thing would be to have the props checked. You need a starting point.

Maybe 2 different gear ratios in lowers? Happened to me with our 353, bought a replacement new XR 1,50 drive from a local dealer and instantly RPM was off, was told it needed breaking in. Boat top speed suffered and boat listed a bit. On the 3rd return to dealer they replaced the lower with a proper 1.50 and all was good.