Ty Lee,

There is no breakdown of the 205 1965 Beaumont Custom V8 convertibles built.  As to how many were/are 283 V8's and how many were/are 327 V8's

Vintage Vehicle will not get into a breakdown of those numbers.  Due to the "ripple effect" it would cause them.   If they did it for one model of Beaumonts. 

Then they'd have to do it for all models of Beaumonts.  Then they'd have to do the same for the Chevelles, Acadians, Novas, full size passenger cars and trucks.

Vintage has no interest interest in opening that "Pandora's box" of work for themselves.   As there are two versions of both the 283 & 327 V8 engines in 1965.

Let's agree the majority of these cars will be 283 V8's 195 HP.   Then 283 V8 220 HP,  327 V8 250 HP and possibly 327 V8 350 HP.

As to what the actual break down of these engines is.  No one really knows.  I'm pretty sure we never will.