SWCDuke

C2 small blocks can be twitchy at the limit and snap into oversteer. This is due to compliance of the front anti-roll bar link bushings, which effectively transfers roll stiffness to the rear with increasing roll, and the solution is to install hard urethane bushings. The OE rubber pillow block bushings are okay. If you would like a little more understeer replace the OE 3/4-inch front anti-roll bar with the 13/16", which was base beginning in about '74. (The lower rear roll center beginning in '68, and the larger front bar combined to increase understeer and yield more stable limit behavior.)

Alignment tuning will get the most out of the CR6ZZs - up to -1 deg. camber all around and as much positive caster as you can get within the range of shim adjustment while still getting the upper A-arm cross shaft mounting nuts fully threaded onto the studs.

The OE wheel rates of about 80 lb/in front and 140 rear give a decent ride and due to the relatively high roll centers, provide good inherent roll stiffness, so huge bars aren't really necessary.

Another good investment is adjustable rebound dampers like Spax or QA-1, which will allow you to tune suspension behavior to your specific driving conditions and preferences.

With the above tuning it should exhibit mild understeer on turn-in, neutral at the limit, and pull close to 1g on a skidpad with about 3-3.5 deg. roll.

Duke

martin2561

Duke Does the above also hold true for the C2 Big Block?

Railroadman

Careful - despite it being a good question, some people get all cranked up when seeing a 2-year old thread!

SWCDuke

In general I would say yes, but I don't have much experience evaluating big block handling. I did evaluate a '67 L-71 a couple of years ago, and it had a definite tendency to go into oversteer with a quick flick of the steering wheel to the left. It was more stable testing to the right. I suspected a rear toe problem, and that was the culprit. The right rear had toe out. We corrected that by swapping 3/32" worth of shims from inside to the outside of the RR trailing arm. Toe-in in is now about 1/32" on each side which is on the low side for the installed bias ply tires, but good for radials.

The transient handling is still a little "spooky" with the bias ply tires. The car got Duntov award in 2018, so he's done with judging, and I'm bugging the owner to buy a set of repro 6" Rally wheels and install a set of 205/70R-15 Avon CR6ZZ. He's beginning to come around on that idea.

Duke