1969 Oldsmobile Cutlass Supreme

1969 Oldsmobile Cutlass Supreme Project


Having a Cutlass in his younger days, this client desired to have another.  He purchased this car in nice, drivable condition.  After putting some miles on it, he noticed several things he wanted to change.  It had a very modest gray paint job, the engine was mundane, and it was a low-optioned car.  In essence, he wanted the car to live up to its SUPREME moniker.  The couple that owns this (now) fine machine planned to drive their Cutlass between Corcoran and their vacation home near the Pacific Coast.  Therefore, our mission to build a smooth, comfortable long-distance cruiser was set in motion.


First-things-first, we lifted the body up away from the frame.  This granted access to clean the frame and coat it with POR-15.  Drilled and slotted four-wheel disc brakes from THE RIGHT STUFF were added to bring the braking system out of the ‘60s.  At the same time, the bushings and steering components were all replaced and KYB shocks were added to control the ride.  EIBACH lowering springs (1.25″ drop) had already been added before we received the car and were left in place.  To this, we added BMR rear trailing arms with polyurethane bushings.  Also included in this kit were larger front and rear anti-sway bars.

A custom steel driveline was fabricated by PERFORMANCE INDUSTRIES in Bakersfield, complete with extreme-duty SPICER U-joints.  A new front yoke was added and the whole shebang was balanced before pick up.

The 17″x 8″ five-spoke alloy wheels were already on the car but needed new tires.  After the car was back together, we determined larger tires would fit.  Pushing the inner-fender boundaries, 275/40-ZR17 Cooper Zeon tires were stuffed under each corner of the car.  Since this is a very common size, the owner should have no problem securing another tire if any are destroyed while away from home.


The original 350 engine had been rebuilt. However, during the last few years, the car had been moved from shop-to-shop and not driven any decent distance.  This allowed significant contamination of the oil.  The engine ran well, but we were starting to notice a light amount of noise coming from the valvetrain.  As the car was nearing drivable status, the fluids were checked.  The oil was registering several quarts OVER full.  While investigating further, we noticed a strong gasoline smell from the crankcase.  As we drained the oil, it filled a 7-quart drain pan almost instantly.  By the time the oil pan was empty, a second drain pan was filled half full.  Large amounts of water and fuel were present.

For peace of mind, the engine was pulled out of the car to check the internals.  Sure enough, the super thin / contaminated oil had wiped out the camshaft (the source of our noise), scored the cylinder walls and wiped-out the protective surfaces of the bearings supporting the rotating assembly.

RPM MACHINE in Tulare was trusted to tear down the engine, assess the totality of damage and re-assemble.  The seasoned rotating assembly was machined to perfection and precision balanced.  The cylinders were honed to produce a fresh surface for new rings.  Since the 350 Olds motor was never really a performance option – a “top end kit” was secured from MONDELLO PERFORMANCE in Paso Robles, CA.  Their hydraulic camshaft, lifters, and aluminum heads were installed in and on the properly-prepped short-block.  400 horsepower was the target for the build, while still maintaining good street manners.

The existing EDELBROCK RPM intake manifold was re-installed and the 625 carburetor stayed in place at that time.  The HEI distributor was freshened up and dual electric fans were added to the remanufactured 4-row radiator.

After the car had been returned to the owner and had been driven for several hundred miles, it came back to DCC.  The owner was tired of dealing with hard-starts in high-heat conditions.  The carburetor would vapor-lock, and it was having trouble dealing with the performance cam, air conditioning, vacuum-assist brakes, etc.  The owner was ready to add EFI to control the fuel distribution.  We had anticipated this stage of the build, so previsions had been made.  The car already had a low-pressure electric fuel pump, but it was located in the engine compartment.  We relocated the small pump back to the fuel tank area and ran a fresh dash-6 stainless-braided fuel line all the way up to the carburetor.  Now that it came back for electronic fuel injection (EFI), we simply replaced the low-pressure pump with a WALBRO high-pressure unit.  After that, a FITech EFI throttle-body replaced the ailing carburetor.

A TH700-R4 had been adapted to the Olds motor during its previous life.  The trans was fairly fresh, so all we had to do is wire the converter to lock-up only in 4th gear and a vacuum switch was placed in-line to allow lock-up only when the engine is ready.

The original rear axle assembly in this car was one of the Olds/Pontiac 10-bolt units with the odd 8.5″ ring gear and 12 (yes TWELVE!) cover-plate bolts.  Therefore, it is called the “12-bolt that is not a 12-bolt”.  We found that there is really no support for this component.  No gears, no new posi units.  So, we got creative with a 1970 Pontiac coupe we had out back in our parts-car lineup.  We stole its regular 8.2″ BOP 10-bolt and had Performance Industries throw in a new Auburn Pro-Series limited slip differential and we re-used the 3.31 gears.  Of course, our normal recipe of new bearings and seals completed the mixture.  It ended up needing one axle as well.


New quarter panels had been installed prior to its arrival to DCC.  The bodywork was finished up and body gaps were set.  The client knew he wanted a dark blue metallic paint.  He chose a 2015 Camaro color, that almost looks black in the shade.  After the body was blocked to near-perfection, it was time for paint.  Epoxy primer/sealer was laid down first, followed by 4 coats of basecoat to ensure coverage and distribution of the metallic components.  Once satisfied, PPG 4010 clearcoat was heavily applied.  Finish sanding then took place, followed by some healthy rotary polishing.


The wiring had already been “handled” before we got this car.  There had been some cutting here and there, but the overall electrical system did not require complete replacement.  An OPTIMA battery was put in place for stability and cleanliness.  Our usual step of adding a 4.3-amp CTEK battery conditioner/maintainer was not skipped, ensuring this classic is ready to go at any time.

First, we installed brand-new original gauges, because DAKOTA DIGITAL was not yet offering VHX-series gauges for this year/model car.  The gear indicator on these cars is at the bottom of the speedometer.  Again, no readily-available overdrive lens could be found so we adapted a curved indicator from a different make/model into the appropriate location.  A Dakota Digital ECD-100 speedometer drive was coupled to an electronic speed sender to allow accurate calibration.

Just recently, Dakota Digital announced that they now had VHX gauges for this model so the car was returned to DCC for this installation, which is now complete.  Power windows, locks and trunk latch were also added.  These are connected to a Dakota Digital keyless setup, which allows wireless remote control of the creature comforts.

The factory AC system was still in-tact.  We adjusted an area of the airbox to allow for headers and other engine components.  A RON FRANCIS dual fan controller is tasked with staging the fans for engine temp as well as AC condenser cooling.

Replacement LED bulbs were used wherever they could, inside and out.  Our usual headlight upgrade was installed since they plan to drive back and forth to the coast.  HELLA H-4 units were used with normal halogen bulbs for now.  In the future, we will be changing those to LED or HID.


Most of the upholstery had been previously refurbished.  Since we had the carpet out and the doors apart for power windows, a generous amount of DYNAMAT sound deadening insulation was added front-to-rear.   The car also got new front and rear windows, along with a new dash pad.

The almost Supreme Cutlass was then taken to MARK’S UPHOLSTERY in Visalia, CA to complete the interior installation.  HANFORD GLASS helped us with the power window adjustments and installed new front and rear glass.


This Cutlass is now in the Supreme category.  In fact, in the last year, the owners have put approximately SEVEN THOUSAND MILES on this vehicle.  We made sure to put it to the test during the “shake-down” and calibrations phase.  80 miles per hour occurs at around 2400-2500 rpm with the converter locked up in 4th gear.  So, the owners can choose their speed, set the cruise control, and enjoy their drive.  Thus, bringing our mission to build a smooth, comfortable long-distance cruiser to fruition.