I'm assuming yes. The block is virtually the same, except the pistons different and other little things. Although the strength of the RC clutch may be comprimised as the rg is more powerful than a standard rc. Its pretty much a case of whether the box is made for the clutch as well.
I'm sure norbie, and fellow modders will be able to answer your query in more of a definite responce, so thats just what i think.