I had a knock on my '94 LT1 wagon. I pulled it apart and one of the mains was wiped out, rotated about 30 degrees, and the crank shaft was cracked right across that journal.
I measured the block at that main cap, and it was good. I ended up putting a new crank, main, and rod bearings in and buttoned it back up. I didn't even remove any of the pistons or the intake manifold, etc. Car went another 150,000 miles and was still running perfectly when I sold it (had 275,000 miles on it at the time).
Bottom line: If it's a daily driver, I'd recommend just fixing what's broke. These engines really don't "wear out" if they are maintained even moderately well.