[Timesink]

If you can find it, Chris Miller's novelization of the movie is hilarious, with loads of scenes and character details that never made the film.

Is this what you're talking about? Or is that a watered-down, "illustrated" (comic book, almost?) version of a different, actual conventional novel you're referring to?

[RichInOC]

That was it. It was a trade paperback, magazine size but a little bit
thicker. It was a novelization that was sort of a cross between what Miller wanted the movie to be like and what it ended up being like. I remember it was well-illustrated (they had a chapter composite picture...great nicknames), and there were even some comic-book sequences in there (I think on the scene where Clorette passes out and Angel Pinto and Devil Pinto argue over what he should do, and also the road trip out to the Dexter Lake Club), but it was mostly text.