Here's the story. I recently converted to D44 front and 14BFF rear. I replaced the calipers brake lines and wheel cylinders in the front and rear. I bled the bloody piss out of the lines, gravity feed...... and the brake light is still on! It was not on before the switch to 3/4 ton. What could be wrong? What should I look for? I just rebuilt the engine too at the same time of the axle swap. A couple of years ago I noticed the brake pedal surging but it stopped in a few weeks so I ignored it. Do I need the master cylinder or booster from the donor truck? I don't know what year it was but I think it was a '74. Please, I would be forever thankful for any help with this problem.