1958 Chevrolet Corvette

1958 Chevrolet Corvette 1958 Chevrolet Corvette
Road Test From the December 1957 Issue of Car and Driver TESTED

To mark the fourth birthday of the Corvette, its proud parents, the Chevrolet Motor Division, have announced the 1958 model which has undergone some extensive but not too important changes on the surface and a few rather interesting ones underneath. Starting right at the plastic body, the use of aluminum reinforcements in the cowl structure, inaugurated in mid-'57, has been extended to include the so-called "rocker panels" under the door openings. Bumpers are now bracketed to the frame in conventional American style, relieving the front and rear body panels of loads that are not rightfully theirs. These two items raise the weight "less than 100 pounds", but for racing, most of it can be unbolted and left in the pits without the SCCA batting an eye.

Uncowled dual headlights show how attractive most American front ends would be if we'd get off this "I'm longer than you are" kick. Just below them are really large holes for blasting fresh air onto the brakes, but on our test car, alas, the "holes" were painted black! More on this later on.

Further production experience with the F.I. nozzles and metering controls permits closer control over the air-fuel ratio this year. The warm-up diaphragm is now more sensitive and the air filter is also changed. On all Corvettes, the generator is now on the right-hand side so that the fan-belt engages the water pump pulley over a far greater arc, reducing slippage at high revs. Common to all '58 Chevy's with the 283 cubic incher are a new distributor rotor and a cap with longer sides to help keep out moisture.

Like most manufacturers, Chevrolet is none too happy about some of the attempts made to bring "boulevard" engines up to all-out F.I. specs. More is required than just a Duntov high-lift cam and a handful of solid lifters, although the factory is not too specific as to what is. What they have done is clarify the picture of available options.

First of all, here is what an absolutely standard Corvette would have (later we will get into what else can be ordered on the car at the time of purchase): The 283 cubic inch V-8 with a normal camshaft and hydraulic tappets (limiting revs to about 5500, as on our test car), a single four-barrel Carter carburetor (#3744925), the "close-ratio" three-speed transmission (also used on other Chevy's with the 283 inch engine), a 3.70/1 ring and pinion, 6.70x15 tires (tubeless or not, to choice) on 5Kx15 disc wheels, and a choice of either the hardtop or the hand-operated folding one.

Options available that do not change the basic car's essentially boulevard character include: Powerglide transmission and with it, a 3.55 rear end; electric window equipment (which is no lighter than the hand-operated kind as reported elsewhere); a hydraulic mechanism for the folding top; and for the belt-and-suspenders types, both the hard and soft tops may be ordered on one car.

To improve performance, one can order either two Carter quads or fuel injection (we have the latter), the manifolds differing slightly between Powerglide and stick-shift cars. But for the most in "go", there is the 290 bhp @ 6200 rpm "D" fuel injection engine which features a 10.5/1 compression ratio, the high-lift cam, solid lifters, an air intake extension to bring in cool outside air, a reputedly "more efficient radiator", and a tachometer reading up to 8000 rpm. Especially designed for this engine, but definitely available on its own, as on our test car, is a really delightful, all-synchronized, four-speed gearbox.

In much the same category are the Positraction limited-slip differentials available with either the 3.70, 4.11, or the 4.56 ratios (and though you can't order it this way, the normal Chevy 3.89 gears will fit the carriers of either the 4.11 or the 4.56 Positraction diffs). To give slightly better side-load characteristics, wider (5-1/2Kx15) rims are available for fitting 7.10 or 7.60x15 tires, racing or otherwise; the difference between the two enabling last minute "gear" swaps to be made at races.