C3-71 LT1 suspension questions

[Peter M.]

Re: I agree.

Joe/Terry/Duke etc,

In my continued quest to learn more about LT'1 I was surprised to see the response-i.e. that the base engine suspension was same as LT1-didn't seem in character for Chevy.

In addition, I thought I recollected different literature pieces that referred to these differences(you are probably aware of these and they are simple mistakes-can't believe everything you read). But just as an example, I have the 71 dealers manual from Carlise and page 10 for Corvette Power teams with the heading "Equipment Included with Optional V8 engines:", the LT1 option has checked in the column next to Special high-domed hood, Heavier duty front stabilizer bar, Heavier duty rear wheel spindle support arms, heavy-duty front and rear shock absorbers, Large capacity radiator, dual water pump and fan pulleys, and finned alumimum valve rocker covers. Is the explanation for this that this is really referring to ZR1 option? Also know I have old road test magazines that mention something along these lines but again could be a mistake. Just writing to learn from you gents as to what the explanation is for these types of inconsistencies. Let me know your thoughts. Thanks as always.

[Duke W.]

Re: I agree.

Keep in mind that "base" suspension Corvettes featured relatively high ride rates and roll stiffness compared to passenger cars, and optional Corvette suspensions were really focused at serious racing, not normal street and highway use.

In 1963 there was no stand alone optional suspension regardless of whether you ordered a base 250 HP engine or a SHP/FI barn burner. Heavy duty suspension components were only available with the Z-06 special performance equipment package, which was aimed at serious SCCA and FIA racers. The suspension components were unbundled to a standalone option in '64 and future years, but since the ride rates double from the base suspension, it is totally unsuitable for street use. With a little bit of camber tuning the base suspension cars have excellent handling. Of course, handling is ultimately limited by tire characteristics and adhesion, so if you want good handling you have to start with the best handling tires. Junk tires equals junk handling no matter what you do to the suspension.

There are many errors in documentation. If you do not have a AIM for your year, you should obtain one. Since this was an engineering document it was continuously changed and updated during production. AIMs are not perfect, all inclusive oracles or totally without error, but are the best source for what parts were required for various options, and the change record section on each sheet leaves an audit trail of most part number changes during production.

What you quote in the dealers' manual sounds like the ZR-1 package, which was equivalent to the '63 Z06 package. The ZR-1 special performance equipment package bundled the LT-1 engine with HD brakes, HD suspension, and I also believe there were some cooling system changes. (The AIM ZR-1 section will have specific details on parts substitution throughout the car.) It was focused at those who wanted to compete in SCCA B-production. I recall there has been at least one ZR-1 owner post to the board. The owners of these rare option cars are usually the best source of actual as built configuration information, and some are very serious and dedicated historians.

Errors in press and dealer information were unknowingly promolgated by the press and GM rarely made any attempt to correct errors after the fact. You know the old saw: "Specifications subject to change without notice." Thats how they cover their a.... You can't believe everything you read, even if it was published by GM, and we are left to sort it all out a generation later. There are production configuration issues that we are still debating, like the "535" L-88 cam question posed by Jon Stachan in a nearby thread. Heck, even Joe hasn't yet figured that one out completely.

Duke

Duke