I agree on the Direct Connection Chassis Book, there's some nuggets in there for the not-straight line folks as well as drag racers. There are a number of editions but I've not had an a chance to compare - the editing and typos are rampant in the 'Carrol Shelby' editions (1984) and maybe all of them. Most of the chapters were first released by Chrylsler as performance Bulletins.

It's worth calling attention to a chapter on car breaking "Rally Preparation". Useful for anyone considering off pavement performance driving in A-bodies, and some mention of Champ-Colts.
Also worth noting is a chapter on "Front Suspension". It touches basic assembly and components but not much on set up other than toe pattern which is covered well.
I *think* some of the original bulletins are on the web but don't quote me on that.

Another good source for both Road Rally and what I'll call closed course non-paved activities is a magazine article by Scott Harvey himself. It is going to be hard to buy but libraries and other enthusiasts will let you read and/or photocopy.
"Scott Harvey and Rally Preparation" Sports Car Graphic May 1967 pp 28-30,70-71
Cool pictures too!

Just for a clarity, the term rally covered a broad range of competitions. I use Road Rally here as the current term for events that share the roads with the public. However often these events are 'brisk' and frequently involve non-paved sections and adverse conditions (night, rain, snow). By closed course events I mean rallies where portions are run on roads closed to the public aka 'special stages', and 'rallycross' type events.