Numbers Matching?

Either way still not a numbers matching engine and would not add value to the car.

If a a rare car then a date code engine might mean something to someone.

Since you know nothing about the $3,000 73 engine I would think putting that money into the 68 would be best if the block will clean up.

My 71 340 had to be bored .040 over to clean up a couple of cylinders. It sat for years without heads.

If you want a running non smoking engine get a cheap 360 for the time being from a running wreck so you can see it run, switch them out and then build the 340 stroker you really want.

Good luck