I think $3000 is definitely do-able. I paid $600 for my Eagle ESP 4340 forged crank....4.100" stroke.....$600 for my Eagle H-Beam rods, and $600 for my pistons. You may have to clearance the block if you go with a real long stroke....And of course you'll need machine work and bearings.
You didn't have much
oil pressure...that's for sure. What's got me worried is that you had a high flow pump with low
oil pressure. Was it a low capacity pan? The engine could have been starved for
oil constantly because the pan was constantly being sucked dry.
Four spun rod bearings would clue me into something else being wrong besides running rich. Clearances could have been off.....But would be led to believe there was not enough oil to the engine....
If you rebuild it, make sure you have a high capacity oil pan if you use a high volume pump.....6-7 quarts at least.
That Clevor combo would probably like some high revs with those heads....I would go with a stroker combo.....probably a 3.85" stroke....match the cam and intake with it. I think you would be very very happy....and would come in under or meet your $3000 budget.