And now you have a 305 CID paper weight!!. You mentioned a timetable that involved engine work. Which way you goes depends on what you want to end up with as a vehicle. With the suspension and brake mods and the lowering, is the end goal some kind of time trial circuit corner cutting beast? Do you want to stay with a numbers matching vehicle or is having a fire breathing 93 octane plus octane booster swilling mongo-rat on the possibility list? Old-school, Gen I small block, or LS?? swap in?? Factory cubes or stroker?? You have to pull the motor no matter what, so is a post-mortem in the works? From the sound of what you say happened, I am thinking that once you pull the oil pan you are going to find that either the oil pan got smacked up against the oil pump pickup and prevented the pump from sucking up oil, or the pickup got smacked by the pan and pushed up so that it was sucking more air than oil, or the pickup got knocked off the pump completely.
Again, based on your descriptions, what you are likely to end up with is a block that, at the least, could be rebuilt but why? Count on the entire rotating assembly being junk, along with the oil pump, cam, lifters, and possibly a few bent valves. Count your blessings if, you can remove the main caps and the crank can be extracted in one piece, the pistons come out with some gentle encouragement; worst case being they are all welded solid to the walls of their respective cylinders and requiring serious time on a boring mill just to get them out; which leads to needing to have all the cylinder liners bored out and resleeving the block. Oh, yeah, the main journal saddles will have to be checked and line bored or honed to retrue them as another possibility--same-same-the cam bearing pockets.
For your new motor, if you go Gen I, or even Vortec small block, maybe give some consideration to tack welding the pickup to the pump end cover. You have to pull the relief valve and spring out to do it, and make sure that the relief valve moves cleanly once you put it all back together but having the tube tacked in place does guarantee that it won't move or fall out. One advantage to the LS generation is that the oil pump is on the front of the block; the drawback is that nothing from the old block or from any other spare motors you or you buddies might have that are G-Body era will fit.
No joy, just a lot of $$$$$
Nick