Hesitation problem 1994 Fleetwood Brougham accelerating from a stop a slight hesitation happens... and between 45-55mph if i increase the gas more profound hesitation happens. I replaces plugs, distributor cap and rotor, wires, fuel pump, filter and fuel pressure regulator.

Try cleaning the inside of the MAF sensor and do the following procedure as well.
Here is the most common cause of surges and stalls at stops and low erratic idle speed and rough idle, it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.