The F250 was sticky valves, stuck on#4, the rockers and springs looked like an oily coal mine, an old Holley carb kept blowing the accelerator pump diaphragm, rear air shocks lost their charge miles ago, etc but the drivetrain is in excellent shape. Noisy foul and neglected in need of TLC.

Soooo filled the motor up with diesel let it soak a few weeks, turn the engine over every day, then drain and refill, run it, a couple of times with new filters. Drain the fuel tank and blow out the 30 year old crap collected there, run it through new gas filters a couple of times, now it's clean. Rebuilt the original Motorcraft 2150 2V carb and toss the l'il holley. Replace the 20 year old Cherry Bomb glass pak (yeah i know) with a $37 napa muffler. And the "senior" truck is back to purring, almost, like a cat. With the new muffler on now I can hear a little leak at the exhaust manifold, sheesh
Compression on all eight is between 128 and 133 psi pretty dam good for an oldie. No more valve/lifter noise.