Copo,
From your pics I'd guess it is a 250, but the way to tell is, can you post the numbers on the flat pad by the distributor?
They will say for example,
F0608CS
The last 2 letters will tell what engine it is for sure.
By the 1970s there were sometimes 3 letters.
That sounds like the "mid-size" BV carb, came on the 194, 230, maybe 250 as well. (There were 5 sizes of Rochester B carb, this is the middle one. The 292 used the biggest one).
