SKU: 81230 IRS Categories: ,

’55-’57 Chevy ExtReme IRS Chassis


With our new ExtReme “Tri-5” full chassis, classic Chevy owners can get that cool, low stance on wide front tires without clearance issues or the extra expense, poor ride quality or leaks of air bags. The real ExtReme bonus is plush street manners AND insane handling capability! Sporting the same suspension design as our other ExtReme products, we’ve been able to outfit the ’55, ’56’, and ’57 Chevys with wider tires, lower stance, and incredible handling without sacrificing ground clearance or ride quality.

Coupled with the newest and most state of the art front suspension geometry design, unique only to the Speedtech Tri-5 chassis is the most bind free rear street suspension available, our road and track proven Torque Arm. This 3-link style suspension allows incredibly smooth transitional movement as the suspension articulates, translating to a smooth ride with amazing handling capability. And, it’s adjustable to cater to your specific needs and driving style! Check out the details of this complete chassis below!

Our new ExtReme full frame comes with a complete front and rear suspension incorporating the same parts used on all of our ExtReme full frames and subframes. On top of that it’s a totally customizable package, so whether you’re looking to build a strict street and show cruiser, a total track beast or you want a combination of both, we can put together a package catered specifically to your car and driving style!

What you get in our standard package:

Fully welded box style ExtReme chassis with high clearance frame rails
Extra High clearance, geometry enhanced Upper and Lower front control arms, powder coated gloss black and assembled with the best components available.
New ExtReme design aircraft spec 7075 T73 forged aluminum tall spindles with heavy duty C7 hubs See the forging process- Click Here
Sweet Mfg. race tuned, high strength power rack and pinion steering unit
Adjustable, splined sway bar with your choice of spring rates
JRI single adjustable shock with Speedtech valving
Draco springs in your choice of spring rate
Engine frame stands for LS Chevy engines
Award Winning IRS set up


All ExtReme shock and sway bar packages will be customized to your specific vehicle. This can be done as you order over the phone, or for online orders our friendly sales staff will contact you to review options when the order is processed.

Factory steering columns may not be the right length for the correct steering shaft angle and may not work with the ExtReme suspension components. We recommend an Ididit steering column for best results. Please speak to your sales rep to order a column from us or to obtain the correct part number.

Black powder coating adds on $800, while some other colors may be more. Your sales rep will discuss color options and pricing with you. If necessary the coating cost will be adjusted when the order is processed.

When ordering below be sure to click “Add To Cart” after making your choices.

**All frame orders will have a $400 crating fee plus truck freight shipping added on at the time of processing. Speedtech has several options for shipping and is dedicated to provide you with the best quality service and lowest cost available to your area. To save on shipping costs we recommend your chassis be delivered to a shipping terminal or a business with a loading dock and/or forklift access.

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