Are all 273 V8's the same?

Exhaust manifolds likely different between B / A and likely engine brackets

On a 'he he' note, in the mid 70's "for about a year" I was swapping stuff around and needed an engine that "just ran." Friend of mine had a " " " " 318 " " " " turned out to be a 273. Anyhow I swapped it into my 70 RR 440-6 body, which at the time had had a 340 in. it was an oil user and leaker, but it ran.

A "then" friend of mine had a 49 GMC he'd swapped in a big Chev six, with Clifford Holley 4bbl, adapted to an A833, and some sort of cam, it was supposed to be "fast." Anyhow one weekend 4 of us were going from one town to another about 55mi away, and discovered "a clear stretch." I whumped that Chevy's *** with all that crap on it with that bone stock wore out 273 2bbl. All it had was headers, and those because they'd been on the 340. HE TO THIS DAY HAS NEVER LIVED THAT DOWN