2001 Astro 4.3 L HELP PLEASE !!!!

Ok here we go good 1 for all the true mechanics in here, I stopped to fuel up and finished started van and went to clean windows in back got back in van check gauges no oil pressure shut van off thought gauge stuck so restarted shut off opened hood and low and behold oil cooler line came off (quick disconnect) reattached filled with oil started no good, spun bearings clank, clank. Towed home replaced bearings torqued everything to specs replaced oil pump (primed it) replaced filtercleaned all metal shavings out of pan and restarted and clank, clank drove 3 blocks away clanking all the way (ha,ha,ha) to a garge to put scanner on and codes P0335 (Crank Postion Sensor) replaced it, and P0341 (Camshaft Postion Sensor) replaced it oil covered computer next to battery thought shorted it out replaced it with newly coded 1 and still same problem only worst now it will not start at all, it turns over like normal for 5/10 secs than a clank then dies for a sec then tries again any help would be great iam just lost ready to put new motor in although this one has 63,000 on it and would it be cheaper to rebuild or used 1?

I've read in other posts that you have to change the oil cooler with a shot engine. The particles stat inside the cooler, then come out to blow up the new engine.

Do the 2001's come stock with an engine oil cooler? I ask because none of my vehicles are near that new. Drew is right though, if it does have an oil cooler for the engine, it has to be flushed before restart. One other thought, have you pulled the distributor and checked the shaft and gear.
My haynes manual says that the distributor shaft mates to the oil pump drive shaft. There is a tab on one shaft and a slot in the other. So, there is a direct mechanical link here between oil pressure and the engine not starting at all. My two cents anyway...

Re cooler: If the new ones still tow 4500 or is 5500 lbs, without the tow package, I'd say they all come with the cooler.
And I've read you can't clean a dirty one. And another fellow said the engine supplier wouldn't give him a warrantee without a new cooler.