Sorry Supercuda I was hands free speak-to-text'ing this thread over my phone while driving and was paying more attention to the road.

Its a 1980 d100 with a 318, manual transmission. Just bought it a couple weeks ago. It was nice enough, had some nice parts in it, and it was dirt cheap, no issues at time of purchase.

It has a 2 barrel intake, a small holley 2 barrel carb (havent even looked at size), MSD 6A, cheap headers, full single exhaust with muffler, low pressure aftermarket out of tank fuel pump. The PO said the engine use to have aluminum heads and a big cam, but that cam got flattened and destroyed so he removed the heads and cam and put the stock iron heads back on and a new cam slightly bigger than stock. He also said the cylinders looked good as well. He changed the oil and filter but didnt remove the pan. I didnt nit pick and grill him for more detailed info, as he was selling me the truck for $700 and it had over $1000 in ignition, carb, headers and exhaust. Even if the engine didnt run it still wouldve been a good deal.

It has a jacked up throttle cable but other than that it has not given me any issues. The oil pressure problem started earlier today. Although it will drop randomly, I noticed it will do it if I come to a hard stop. Sometimes when I stop I'll just watch it gradually drop to about 10lbs, then slowly to zero. Thats what made me think there's crud in the pan and its getting sucked up and clogging the pickup tube, and when I shut the engine off and shake the truck, it disturbs the clog and things go back to normal until it clogs again. It could be debris from the destroyed camshaft as well (if that even happened).