IRC, your '65 trans is actually has the old buick round bellhousing
pattern, with an adapter that allows it to bolt to the caddy engine.
You can use any '68 up caddy trans to bolt to the '73 eldo engine,
but fyi: your '65 trans is a "switch pitch". To retain that feature,
you'll have to swap the innards from your trans into a later bop case.
> I'm woundering how difficult would it be to drop a 73'eldorado 500
> into a 65'deville? Is the bellhouse bolt patter different? is
> room? if anyone has answers i'd really appreciate them.