Are you saying "complete" as in 'ready to bolt on and go play'? If so, $4k - $5k is probably a good starting point. The rarer (--more desirable) the head is, the more it will fetch.
There was nothing special about the Rucker, performance-wise. Before spending a lot on it I would buy a new Miller from Steve Serr. I wouldn't pay over 3 grand for the Rucker unless it means something special to you.
I jest found a Rucker over head for Model A Ford in the rough, can anyone give me any information about how many were made and when they were manufactured and what they may be worth. Thanks