Technically, there is no "numbers matching" in 1965. The engines weren't coded to the chassis number. But it's cool you have the original engine.
When I rebuilt my 273, pretty much everything was available from the normal sources. The only exception was oversize pistons. I believe these are still available from Egge.
Is this a standard 2-bbl 273 or the 4-bbl Commando? Some of the Commando bits are harder to find. Aside from the dress-up parts (valve covers, air cleaner), it's getting tough to locate the correct points, high compression pistons, and solid cam.
