@Hugomartin
The reason why you have oil coming out your dipstick, is because of it having 20 psi compression on a couple cylinders. All the extra compression those cylinders should be making is sneaking past the rings, and pressurizing your crank case, which shouldn't be pressurized.
The reason you have 20 psi compresion, could be from really bad rings, cracked rings, warped cylinder, cracked or scorn cylinder, or a hole in the piston.
Itll need to be completely stripped down, inspected thoroughly, and at the very least, cross hatch honed, new rings, seals, and bearings. But will possibly need machining.
If you did a compression test and its getting anything like 20psi on any of the cylinders, the engine needs to be rebuilt, ground up.
To rebiuld it, it needs to be pulled.
(Info for next time, not picking on anyone at all, we all learn)
You would have been better off pulling the whole engine complete, and torn it apart on a stand. Could've had the engine out in about 2 to 3 hours, and torn down to a bare block in an hour or so.
Even at this point, pull the engine. What you need to do to be able to fix it, is going to be done outside of the truck, engine on a stand.
Also, only thing id say you have to worry about keeping in order are lifters, pushrods, and rockers, and later, rod and main cap bolts. Bolts i wouldn't worry about. Personally, if i were you, when i put the engine back together, id just throw away the old head bolts and intake bolts. Head bolts will stretch, and untemper, and your intake bolts will get rusty. Just buy a new set of head bolts at the parts store, maybe.$50, well worth it. And get 12 new intake bolts at the hardware store, just match the thread and lenght. Id suggest getting grade 8 or stainless steel bolts, but thats up to you.
For future reference, proper procedure for either pulling the heads or pulling the engine, is: coolant, oil, wiring harness, fuel and vac lines, accessories and bracketry related, carb or throttle body, distributor and wires, plugs, exhaust pipe or donut, exhaust manifolds, intake manifold.
After that if your pulling just heads, pull heads. Or if your pulling the engine, leave the heads, and pull starter, engine mount bolts, bell housing bolts, and out it comes.
If done right, will go quite smoothly.
My friend and i recently pulled the engine in his C20. It went from running, drive into his garage, to engine out and stripped to a shortblock in about 2 and a half hours. Block was still warm, haha.
Good luck with everything. And don't feel bad, we all learn.