You might want to check out this Hot Rod Magazine article from May 1955.

http://www.earlycorvettes.com/linda/mcgurkhotrod/mcgurkhotrod001.pdf

As Tim stated, the Corvette 235's used a stock 261 cam. Another option that you might want to look at is a cam referred to as a Bulldog or a .254./.264. It is made by Delta and sold by a few vendors including Tom Langdon.

Matt