Have 91 D150, with 318. I want this thing to run as decent as possible. My air pump pulley has already flown off the engine, so I just took the whole pump off. Likely looking to do an EGR delete and whatever modifications I can pull outta my hat without spending crazy money. Mine is so old, as long as it has a muffler that's all that matters as far as emissions, otherwise I'm exempt. Any tried and true ideas ?

If the pulley has come off, then it isn't dragging. I'd just leave it. I wouldn't bother with an EGR delete. What are you wanting to do with the truck? If you just want it to run smooth, do a tune up. Cap. rotor, plugs and plug wires.

Like grouch said, a tune up goes a long ways. When I bought my W250 the spark plugs were pretty worn out and had twice the gap they were supposed too. Plugs/wires/cap/rotor helped improve the idle quality a great deal, cleaning the throttle body helped too. You could check and see if it has any trouble codes, not all of them will illuminate the engine light. Maintenance goes a long ways. I like checking all the sensors to see if their values are in spec, after 25+ years things can get out of wack and I think little things like that help you get a bit smoother running engine, but that's just me.

If its leaking or stuck open it's worth the delete.