'88 Oldsmobile
Cutlass Supreme Classic


Older pics

A short history

Manufactored Aug. 1987 it has had 2 or 3 previous owners before purchased by me in June 1998 with about 75K on the clock. Obviously repainted, but straight and, for a rustbelt car, suprisingly rust free.

The first thing required was replacement of the worn out KYB shocks and so they were replaced within the week with a set of Koni shocks. Followed by Hellwig anti-sway bars front and rear, using new Energy Suspension poly bushings. These along with the wheels and tires, once they were cleaned up, were transfered over from the Malibu. Whereas the B-body spindles from the Malibu had to wait until that car was junked.

With the basic suspension needs addressed, I could relax a bit and ponder other changes. One being to replace the rear control arms with Hotchkis boxed arms. At the time I installed those, I also installed the rear cargo coil springs from the Malibu, but they were later replaced with proper sedan cargo coils (cc627) as the wagon springs raised the rear of the car too high for my liking. Although they did give the car a nice rake. :)

Having come across some basic instructions on how to swap the sweep style (aka granny pak) instrument cluster for the Rallye Pak cluster, that was done once I acquired a Rallye Pak cluster. With a couple differences from stock, I kept the coolant temp, and oil pressure idiot lights functional (always nice to have a backup). And later was able to make the Low Fuel light operational (a pic of it). The most difficult part was locating an O/D shift indicator for the cluster, most with the Rallye Pak also had the floor shift, therefor lacking the indicator, so said indicator is not very common.

By this time the Malibu had been parted and junked so I was ready to install my B spindles along with Moog 5662 (3rd gen Z/28) front springs. After the shocks, easily the most dramatic change to that point. The 11" brakes bring the braking capability to were it should have been to begin with, and the 5662's allow me to think about scaling back on sway bar size, which would improve the ride quality.

Next the exhaust system was replaced with the Walker replacement for the stock 442 system. Although hardly the ultimate system for performance, it is virtually a bolt-in, provides a nice exhaust tone and the all important dual outlets.

It didn't take very long before a notorious weak point of the 200r4, the pump vanes, to self destruct bringing about a trans rebuild. At the same the time the trans was rebuilt (with hardened pump vanes) I had a B&M Holeshot converter installed and the original 2.56 rear axle ratio was changed to 3.42 with limited slip. With the 200r4, this ratio works very nicely, no "bog" offline and as this converter retains lockup, the highway rpm's remain very reasonable. In fact sometimes converter lock/unlock almost feels like another gear.

Installed Flash-to-Pass, this was way too easy and something I'm surprised GM never offered until much later.

Started making some braces. First replacing the fender braces with braces made of tubing. Second, making a rear frame brace. Next is a front frame brace.


Replaced the old rear 15x7 wheels with 15x8.5's and increased the rear tire size to 255's. Then I moved the 15x7's to the front, losing the 14's, and switched to 225's for the front.

Installed a Poncho GP front crossbrace, and here's a pic of the rear seat braces installed.

Replaced the tired original body bushings with new Energy Suspension poly bushings. A pic of the old bushings is here.

To protest "tire roundness checks", the 7.5" rear broke during the 1-2 shift. To reduce the possibility of a repeat, the 7.5" was replaced with a 8.5" rear axle from a GN, as before w/ 3.42's and posi. I guess now it truely is ready for a 403. In the process I left the rear sway bar off to see how that effects the ride and handling. Here the install is almost complete. The rear sway was later reinstalled

Replaced the cargo coils out back with a set 5379's and air bags after the cargo coils sagged.

As part of the ECM project (a peek), I've been trying to get an adaptor made to do away with the oddball RN socket. My first attempt was to try and get Olimex to make the board, that proved to be a frustration. Apparently they did not understand the purpose of the board and then claimed they lacked proper information to make the board. This is after they where provided with the files they had requested to be provided. Apparently they are incapable of working with modern board design files.

Finally(!) finished the cruise control retrofit. This was done with all factory parts resulting in an installation that appears and looks like it was installed by the factory. Only way to tell otherwise would be to check the SPID.

Lots of other little odds and ends along the way, but that's the highlights to date.

Waiting in the wings
(time and weather permitting)

Future plans and ideas

Replace the 307 with a 403. (A 403 longblock is currently in my possession and awaiting build-up) This will be run using the electronic Q-Jet and a computer controlled distributer by way of the 1228330 ECM which has already been hacked

Paint! (It really needs it)

Swap the bench seat for buckets and a console (welding required)

Convert from a carb to port injection (Big changes, lot's of work, still iffy)


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