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The official club for enthusiasts of the

Oldsmobile Cutlass Supreme SX

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As of February 6, 2016 there are 665 Cutlass SX cars in the Registry!
SX455 is the official web site for the Oldsmobile Cutlass Supreme SX. Since 2005, we have been registering and documenting everything there is to know about these rare muscle cars. All visitors to this web site have access to some general information about these cars. For a fee, there is a ton of other data, documents, and info on this site all Oldsmobile and muscle car enthusiasts will find informative and interesting. If you are thinking about purchasing a Cutlass SX, do your research before you make an offer.

Scroll to the bottom of the page for Club Membership and Cutlass SX Car Registration options and fees.
Thanks again for visiting SX455!

Most muscle car experts will agree that Oldsmobile reached its pinnacle in 1970, the same year Oldsmobile introduced a notchback intermediate called the Cutlass Supreme.

In 1970 and 1971 this new Oldsmobile was available with a special option called the Y79 Performance Package and the car was named the Cutlass Supreme SX. The Cutlass SX featured several 455ci engine options, a 400 Turbo Hydra-matic transmission, a cut out rear bumper with dual exhaust, special SX badges on the fenders and other goodies not found on a standard Cutlass Supreme.

In 1970 there were three 455ci engine options for the Cutlass SX. In 1971 there was only one Cutlass SX engine option. These engines offered up to 365HP and 510lbs of torque!

The production numbers for this two-year-only (1970 & 1971) model are less than half of the highly collectable Oldsmobile 442 models, plus many of the Cutlass SX cars were sent to the junk yard crusher before the car became collectable. The Olds Cutlass SX is truly a very rare GM muscle car!

ALL 1970 and 1971 Cutlass Supremes had the same basic VIN codes, so identifying a real Cutlass SX can be difficult. The Cutlass SX cars are valued at 20-25 percent more than a regular Cutlass Supreme model. If you join, you will have access to Spotter Tips, Tech & Spec Data and other helpful information needed to identify a real Cutlass SX. We also have an detailed SX Price Guide for year, model, engine, condition and available options to help you determine the value of a 1970 or 1971 SX Coupe or Convertible.

The Cutlass SX is certainly THE "undiscovered" General Motors muscle car, and will continue to gain in popularity and value as more collector car enthusiasts discover these cars.
Sophisticated styling, luxury options and big block performance make the Cutlass SX a great gentleman's muscle car. If you own a Cutlass SX, or just want to learn more, check out all the content on!


Click Here to Join SX455 Today


Annual SX455 Club Membership $25. For Cutlass SX Owners
SX455 Members get their car added to the official SX Car Registry. You'll get a User Name and Password to access ALL the data, Olds factory documents, literature and CutlassSX magazine articles on You can upload unlimited photos of your carto your member profile page, post questions to the club message board, andmore!

One Year Web Site Access 
$25. For non Cutlass SX owners

You will get a User Name and Password to access ALL the data. If thinking of buying a Cutlass SX be sure to check out the Spotter Tips and Tech and Spec Sections of the Site. WE also offer a Price Guide. Plus tons of Olds factory documents, literature and articles.

RegisterYour Cutlass SX $10. Add your car to the SX455 Registry

The SX455Club documents all 1970-1971 Cutlass SX cars. Since Oldsmobile did not keeprecords on these cars, registering your Cutlass SX helps to develop andmaintain a history of these rare cars. Register your Cutlass SX and you'll receive a User Name and Password allowing you one month access to ALL the info, literature and data on

SX Reseach: 30 Day Web Site Access $15. For non Cutlass SX owners is the ultimate Cutlass SX resource. You will receive a User Name and Password giving you access to all the data on this web site. Discover how to identify a real Cutlass SX via the Spotter Tips and Tech & Spec info. Access official GM literature, magazine articles, build sheets, and other data. Plus you can post questions to the Message Board. Tons of great content for any car hobbyist or Oldsmobile enthusiasts!




Add your car to the
SX Registry - Free
SX Registry Form
Print, Complete & Mail Form


   Get  Access To:

SX Spotter Tips

Build Sheet Info

Tech & Spec Info 

Magazine Articles

Factory Literature

SX Price Guide

Member Directory

Message Board

Plus much more