UMI Performance 78-88 GM G-Body 1in Solid Chrome Moly Rear Sway Bar - Red

Bright Red One Inch Solid Rear Anti-Roll Bar for the 1978-1988 GM G-Body

Same engineering as UMI's gloss black rear bar, finished in bright red powder coat for a build where the underside gets looked at. It is a one inch solid 4140 chrome moly anti-roll bar that bolts to the factory brackets on the rear end housing and takes body roll out of the back of the car.

The manufacturing route matters more than the colour. UMI hot forms and heat treats the bar as one piece rather than cold bending it, and states plainly that it will not sell a cold bent bar for this application because of premature failure. The trade-off is a visible surface texture under the powder coat, which UMI documents as expected.

Key Features

• One inch solid section in 4140 chrome moly.
• Formed hot and heat treated in a single piece, not cold bent.
• Twice the tensile and yield strength of a competitor's cold bent bar, per UMI.
• Direct bolt-in at the factory rear location with no extra parts.
• Complete fastener set supplied: four M10 bolts, eight M10 washers, four M10 locknuts.
• Compatible with both factory and UMI tubular rear trailing arms.
• Bright red powder coat.

Fitment

UMI publishes this bar for the full 1978-1988 GM G-Body vehicle list. UMI publishes year, make and model only for this part number and lists no submodel or trim breakdown, so the fitment tags on this listing stop at model rather than inventing a trim.

Rear axle requirement, and the single most important filter on this part: the bar bolts to the factory rear end housing brackets. UMI's product page states it does not fit a Ford 9 inch rear, and UMI's Stage 3 kit page states more generally that the bar is designed to fit factory rear end housings only, with aftermarket rear ends requiring a chassis mounted bar such as UMI's 3044. Those two statements are consistent, and the broader one is the rule to buy on: factory housing only.

Specifications

What's Included

• One 1.000 inch solid 4140 chrome moly rear sway bar in bright red powder coat
• Four M10 bolts
• Eight M10 washers
• Four M10 locknuts
• One installation instruction sheet

That is the complete contents. No grease packet, bushings or end links are supplied, because this bar mounts solid to the factory rear end housing brackets rather than through isolators.

About UMI Performance

UMI Performance builds chassis and suspension parts at 509 Hemlock Street in Philipsburg, Pennsylvania, using North American raw material from USA steel suppliers, machine-guided precision DOM tube bending, laser-cut plating and welds laid by skilled and robotic welders. Colour is the only variable between this bar and its black sibling; the forming, heat treatment, hardware and fitment are identical, and both are made in the same Pennsylvania shop.

Related Parts

• UMI 3035-B 1.250 inch solid front sway bar for 1978-1988 GM G-Body
• UMI 303534-B solid front and rear sway bar kit for 1978-1988 GM G-Body

FAQ

No. The bar picks up brackets on the factory housing, so UMI publishes it as fitting factory rear end housings only and states specifically that it does not fit a Ford 9 inch rear. If the car has a non-factory housing, the correct part is a chassis mounted bar such as UMI's 3044 rather than this axle mounted bar.

Bow down. UMI's sheet states the bow should face downward so it clears the differential housing. Fit it the other way and it will foul the housing, which is the one orientation mistake worth double checking before the bolts go in.

UMI publishes 45 ft-lb with a torque wrench, or moderately tight with normal hand tools, in its own words. Do the final pass with the rear suspension sitting in its normal operating position rather than hanging at full droop.

Everything you need is supplied: four M10 bolts, eight M10 washers and four M10 locknuts, and the bar drops into the exact factory location with no additional parts. Nothing factory has to be reused except the mounting brackets on the housing itself.

Yes. UMI states the bar works with factory trailing arms and with UMI trailing arms, and UMI's own G-Body rear control arm kits carry reinforced sway bar holes in the lower arms for exactly this combination.

Because the bar is hot formed rather than cold bent. UMI publishes that a hot formed unit is expected to show some degree of surface texture, and it treats that as the price of a heat treated bar with twice the tensile and yield strength of a cold bent one. UMI states it will not offer a cold bent bar for this application because of premature failure.

Yes. UMI offers the bar powder coated in bright red or gloss black, and the diameter, material, heat treatment, forming process, hardware and fitment are identical. The suffix on the part number is a colour code.

It will shift balance rearward, which is usually the goal on a stock G-Body that pushes wide. If you want to raise overall roll stiffness without changing the front-to-rear balance as much, UMI also sells the matching 1.250 inch front bar and a combined front and rear kit.

No. An anti-roll bar only reacts to a difference in wheel travel between the two sides, so it does not carry static weight, does not change ride height, and does not change the straight-line spring rate.

UMI publishes no exhaust or driveshaft conflict, and the bar sits in the factory position with the bow turned away from the differential. On a car with a custom exhaust routed over the axle, cycle the suspension through its travel and check clearance before the first drive.

No. This bar bolts solid to the brackets on the rear end housing, so there are no isolator bushings and no end links in the design or in the kit.

UMI publishes a two year warranty from the original date of purchase against defects in materials and workmanship, to the original purchaser only, and it is not transferable. The same policy excludes misuse, exceeding the design limits of the product, improper installation, altered product, non-UMI components, incidental costs such as towing and labour, and normal wear items including bearings and bushings. UMI also states it cannot guarantee compatibility with other manufacturers' components. Note that the printed sheet in the box still carries an older, narrower disclaimer that predates the current two year term. The policy page is the current document. Neither is a Black Ops Auto Works warranty.

Installation Instructions

1. Assemble the tools UMI lists: a wrench and socket set, a three ton floor jack and two jack stands.
2. Position the jack under the differential housing, lift the rear of the car and transfer it onto the stands.
3. Unbolt and remove the original bar, soaking seized fasteners with penetrating oil first if needed.
4. Offer the red bar into position with its bow turned downward so it clears the differential housing.
5. Pass the supplied M10 bolts through from the outside toward the inside of the brackets.
6. Add the flat washers and locknuts, and bring the four fasteners up evenly in stages.
7. Set the final tension at 45 ft-lb with a torque wrench, or moderately tight with normal hand tools, which is UMI's published wording.
8. Complete the final tightening with the rear suspension resting in its normal operating position.
9. Put the car back on the ground, drive it briefly, then re-check every fastener.

45 ft-lb is UMI's own published figure for this bar. Do not carry over torque values from UMI sheets for other part numbers, and note the sheet's single reference to a 4034 is a copy-paste artifact from the A-Body sibling part.