Car of the Week: 1968 Cutlass Supreme – With W-31 power
Old Cars reader wanted a Cutlass like his dad’s. He not only found one but decided it needed W-31 power!
Photos and Story by Old Cars reader Jon Wessel
My father was an Oldsmobile dealer from 1966 until the end in 2004. When I turned 16 years old in 1971, my first car was a 1969 Cutlass Supreme convertible off the used car lot. It was pale yellow with a black interior, bucket seats and chrome Super Stock I wheels. I was in seventh heaven. After a few months, it had to be returned back to inventory to be sold, but you never forget your first car.
In 2018, I decided to go back to my roots and find a 1969 Cutlass Supreme convertible. I actually did find a twin to my ’69 — it was even the same color combination — but the price was far more than I wanted to pay. During my search, a particular 1968 Cutlass Supreme hardtop caught my eye. It wasn’t a convertible, but had a lot of eye appeal. It had the louvered hood from a 4-4-2 instead of the flat Cutlass hood. I didn’t think the paint color was correct, but I liked it. I kept searching, but the more I looked, the more I kept returning to that car. Finally, I called the seller, a classic car dealer in the northeast. He sent me a copy of the firewall data tag which confirmed that the color was not the factory color. He assured me that the paint job was very nice and there was no evidence anywhere to be found of a color change. The car looked great and the undercarriage was especially clean. It was advertised as having 44,000 miles and was a Canadian-built car, which was interesting. We finally struck a deal and the car was mine. That is the car you see on these pages.
The Olds arrived a couple of weeks later, and it was as nice as was advertised. I believe the claimed 44,000 miles is true. The incorrect hood and paint were what gave the car eye-appeal, but also gave me the opportunity to go down a different path. I wasn’t concerned with keeping it 100 percent correct.
In 1968, Oldsmobile offered a performance package on the Cutlass line called W-31. It was a brutal car designed for the drag strip. The W-31 package included a 350-cubic-inch engine with a high-lift camshaft, larger valves, specific harmonic balancer, specific four-barrel carburetor and distributor, four-speed manual transmission and dual exhaust. Forced Air Induction, with twin scoops under the bumper and 4-in. hoses funneling outside air to the carburetor, was part of the package. It was rated at 350 hp. Due to the camshaft and its lack of vacuum, an automatic transmission, power brakes and air conditioning were not available. Most W-31s were low-budget strippers low on options and weight in order to turn better times in the quarter mile. The W-31 option was available on the upscale Cutlass Supreme, but the high-output engine was not included. This was because the Cutlass Supreme included a 310-hp engine as standard equipment, and also because it was thought the Supreme buyer would want an automatic transmission and would not be happy with the erratic idle of the high-lift camshaft.
My plan was to build a tribute Cutlass Supreme W-31, erratic idle and all. The task was assigned to Carl Cones and his crew at C&J Classics and Muscle Cars in Lebanon, Mo. I proposed to him the idea of a Cutlass Supreme W-31 with the erratic cam, but also with power brakes, automatic transmission and air conditioning. He felt he could come up with a cam that had the trademark W-31 choppy idle, but still produce enough vacuum to run the accessories. Since, at that time, the aftermarket was producing the Forced Air Induction setup, we could capture the look and sound of a W-31 without scrimping on the luxuries.
The Rocket 350 was removed and the heads were sent to the machine shop for larger valves. The rest of the internals were checked and found to be good, so they were left alone. The high-lift cam, along with new lifters, timing chain and a reproduction W-31 harmonic balancer, were installed. High-flow exhaust manifolds were also installed. Since a real W-31 had the alternator located on the passenger side, we wanted to keep that look. That necessitated fabricating special brackets to enable installation of the Vintage Air compressor on the driver side low enough to provide room for the large air intake hose. A stainless four-core radiator was painted black and installed. For fuel management, a FiTech fuel-injection system and high-pressure fuel pump were installed.
The OEM transmission was a two-speed Jetaway. It was jettisoned in favor of a TH-200-R4 four-speed automatic with overdrive. The two-speed shift pattern indicator in the floor console was updated to reflect the new four-speed transmission. My thinking was that if an automatic transmission had indeed been available in a W-31, it would have been a heavy-duty unit with very crisp shifts, and that’s what we spec’d for this car. Out back, an anti-spin axle with 3.73 gears was utilized.
The suspension was left alone except for the addition of boxed lower control arms and a rear sway bar. The front brakes were converted to discs, which required replacing the 14-in. wheels with 15-in. versions. The reproduction chrome Olds Super Stock I wheels measure 7-in. wide in front and 8 in. at the rear. Redline radial tires were installed, and the steering box was converted to quick-ratio.
Unlike its big brother 4-4-2, the W-31 did not use a notched rear bumper with trumpet exhaust tips. This car continues the correct look with the exhaust tips dumping at the edge of the bumper.
The interior was in good condition overall, but the front seats had a couple of seams that had split. I was hoping to have them sewn up, but that didn’t work, so new seat covers, along with a new headliner and new carpet, were installed. The dash was in excellent condition. The center pod houses the speedometer, and it was left alone. The left pod was upgraded from idiot lights to gauges for fuel, oil pressure, voltage and water temperature. The right pod was updated to a tachometer. The gauges were designed to blend in as much as possible with the OEM speedometer.
I now have a beautiful ’68 Cutlass Supreme that does what General Motors would not. It marries the luxury of a well-appointed Cutlass Supreme with the brutal power of a W-31. Some might call it a sleeper. Sitting at a stop light, with the air conditioning blowing cold and the car shaking with the high-lift cam’s erratic idle, I can’t help but smile. It’s the best of both worlds.
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