98 e-150 brakes pull

I have replaced calipers, rotors, and brake pads and still the brakes pull hard right.
The brakes were OK for a couple hundred miles now are pulling again.
Any help would be appreciated.

What's the milage on the van.f it is really high, Id replace the front brake flex lines and bleed the system.

The van only has 44,000 miles on it.

It's a good possibility that the LF hose is blocked. Pull the LF caliper off the rotor, apply the brake, and see if the piston moves. Even if the piston does move, the blockage could be causing the LF caliper to apply slower than the RF, causing your pull. Does the vehicle also pull to the left momentarily after the brakes are released? That would reinforce the possibility of a blocked hose.

Try to lube any caliper bolts, slider bolts, the metal surface of the brake pads that comes in contact with the caliper and caliper mounting bracket. You may need to file to make sure it's smooth.