help with 273
My advice is to check your numbers. If the casting date from the side of the block, the engine assembly date stamped on the front of the block, and the car build date on the fender tag are all jive then it's probably the original engine. You can also check the heads and manifolds for the correct casting number and casting date.
If it is the original engine at least hang on to it because it makes the car more valuable, not matter what you decide to do.
If it's not the original engine, do whatever you want.