What time period are you considering? The farther back you go the harder it is
to find a diesel that fits within your requirements. Even the "small" ones of the
'60s to early '70s that fit the size envelope are pretty hefty and the horsepower
is a lot less than the 283 V-8. Which is one of those things where it isn't really
a matter of one to one equivalency for a variety of reasons, but they'd still not
fulfill the requirements. Modern Volvo-Penta marine diesels would fulfill all of your
needs but, they're all post 2000.
Have you considered a Boeing 502-10MA gas turbine first used on the S-Tank?
Dimensionally it could fit and the weight would be about half the 283. The 553
version used in the production S-Tank could also possibly be made to fit, but the
300 hp of the 502-10MA would give you enough horsepower.

Of course if you want something the size of the 283, there's always the marvelous
Oldsmobile/Cadillac diesel conversion of the Olds small-block V-8.

502-10MA manual including dimensioned drawings. The overall length of the engine
as installed, 41.5" w/out inlet bell, 45" with inlet bell; is easily within the envelope of
the 283 with Hydromatic transmission; 28" + 24"+/-. Plus yer laughin' with the 24"
diameter.
https://archive.org/details/B-001-001-962