Tech9

Printed in The American Tri-Five magazine in Volume 4 : Issue 5
Over the last 60 years, companies have constantly searched for the hot ticket when it comes to suspension upgrades for Tri-Fives. There's been no shortage of products to come through the market; the good, the bad, and the ugly...aimed at everything from traction on the dragstrip to carving corners around a roadcourse, we've seen them come and go. Fortunately, with advances in modern technology, there is no shortage of solid, reliable options available these days to make your car the best it can possibly be for its intended application.

Heidt's is no new name; with almost 30 years in the game, they've had a focus on Tri-Fives for quite some time. Many of you probably have their ultra-popular drop spindles on your cars, and their triangulated 4-link rear suspension is a widely used option amongst hot rodders and Tri-Five owners alike. But what if you're after something more, the upper echelon of handling and a wow factor that can't be beat? Heidt's has you covered with their bolt-in IRS setup!

The focal point of this kit is "bolt-in:' That's right, the kit shown here can be installed on a stock frame without ever rolling out a welder. A few precision measurements, a few holes drilled to the frame, and unlike some of the other IRS options available out there, this setup is installed underneath a stock floor pan, no modification required! On top of that, Heidt's patented center section is 9" based, so coupled with their high-horsepower CV axles, it is worlds stronger than the Dana 36 or even Dana 44 options that make up some of the popular "C4 suspension" setups available. Add the additional power of inboard mounted Wilwood brakes, and you've got a setup that is not only pretty, but highly functional as well.

This kit can be had on its own for about $9,300, or as-shown on an all-new Woody's Hot Rodz OE chassis, ready to slide under your Tri-Five for $22,371, including powdercoating, steering setup, Wilwood brakes and full Heidt's front suspension. At a price point of roughly half the other IRS chassis options on the market, the Heidt's IRS setup is an appealing option for the money, no matter how you slice it!
1.) Woody's Hot Rodz served as the test bed for the Heidt's IRS kit you see here. Joe Shinliver, accompanied by Scott Diedrich and Mike Ruth of Heidt's were all hands on deck for this install, and we'll take you through it step by step!
2.) Bolt in MEANS bolt in! The upper saddle mounts are contoured to the frame, and require zero welding whatsoever.
3.) You'll need to drill holes in the frame for the upper saddle mounts. Being as this chassis was powdercoated before this installation, this was done ahead of time. But simple, nonetheless.
4.) Once the upper saddle mounts are in place, the upper crossmember is bolted in.
5.) With the upper crossmember in place, the third member and housing can be lifted up and bolted in. We pre-assembled the third member, but imagine assembling a 9" with really short axles.
6.) Next, the p1mon support plate is bolted in place. This helps ensure everything on that big center section stays where it should by utilizing diagonal tubular braces
7.) All supported! Onward we go.
8.) The billet hub bolts into the knuckle, much like a late model car would. This makes them individually serviceable, if you can manage to wear one out!
9.) Tubular, dude! Lower control arms are completely adjustable using heim joints, mounts are integrated into the center section.
10.) Blue Loctite will be your friend on this project. Don't be afraid to use it, things like axle bolts, hub bolts, and control arm bolts can benefit from a little extra insurance.
11.) Once your lower control arm is in place, the hub can be bolted on. Leave it hang, having it moving freely will help here in a few steps.
12.) Next up come the brakes. Some of the older crowd will recognize this setup as being strikingly similar to a Jag setup, wildly popular with street rodders in years past. Without the wheel itself directly attached to the brake rotor, the brakes effectively work better. On top of that, it makes getting the wheel on and off infinitely easier
13.) Time for the axles. These high HP units from Heidt's are made for abuse. They bolt on at the axle flange from the center section and are splined with a large retaining nut at the hub like most IRS cars. No rattle gun in use here, these need to be torqued to spec.
14.) With the lowers and the axles in place, it's really starting to look like something! On to the uppers...
15.) The Heidt's setup uses heim joint ends throughout, so no binding, and alignment will be adjustable across the board to meet whatever your needs are, be it aggressive road course racing or just cruising the backroads. The shown offset bushings are used in the upper link mounting points.
16.) Attach the upper link to the inner mounting point first, and adjust it to a halfway neutral position with the locknuts left loose. This will make attaching the hub and spindle a breeze.
17.) Attach the upper link to the spindle. Again, don't forget the offset bushings, these will allow everything to move freely with no binding.
18.) Getting down to it! Next up are the shocks. Heidt's recommends a liberal application of anti-seize to the coil spring adjuster threads. This only makes your life easier when making ride height changes once you're finished up.
19.) Once you have your coilovers assembled, bolt them in place.
20.) Assembled and looking killer!
21.) The forward struts helps with any kind of rotational movement and help act as a traction bar of sorts, if you will. Installation is fairly simple. Locate and drill the holes to the crossmember, bolt it in place, and bolt the struts in.
22.) All finished! Heidt's provides alignment specs for this setup with their instructions, so your local tire and wheel specialist should be able to get it squared up with no problem whatsoever.
Click here for the IRS rear end.

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Printed in The American Tri-Five magazine in Volume 4 : Issue 5

1.) Woody's Hot Rodz served as the test bed for the Heidt's IRS kit you see here. Joe Shinliver, accompanied by Scott Diedrich and Mike Ruth of Heidt's were all hands on deck for this install, and we'll take you through it step by step!

2.) Bolt in MEANS bolt in! The upper saddle mounts are contoured to the frame, and require zero welding whatsoever.

3.) You'll need to drill holes in the frame for the upper saddle mounts. Being as this chassis was powdercoated before this installation, this was done ahead of time. But simple, nonetheless.

4.) Once the upper saddle mounts are in place, the upper crossmember is bolted in.

5.) With the upper crossmember in place, the third member and housing can be lifted up and bolted in. We pre-assembled the third member, but imagine assembling a 9" with really short axles.

6.) Next, the p1mon support plate is bolted in place. This helps ensure everything on that big center section stays where it should by utilizing diagonal tubular braces

7.) All supported! Onward we go.

8.) The billet hub bolts into the knuckle, much like a late model car would. This makes them individually serviceable, if you can manage to wear one out!

9.) Tubular, dude! Lower control arms are completely adjustable using heim joints, mounts are integrated into the center section.

10.) Blue Loctite will be your friend on this project. Don't be afraid to use it, things like axle bolts, hub bolts, and control arm bolts can benefit from a little extra insurance.

11.) Once your lower control arm is in place, the hub can be bolted on. Leave it hang, having it moving freely will help here in a few steps.

13.) Time for the axles. These high HP units from Heidt's are made for abuse. They bolt on at the axle flange from the center section and are splined with a large retaining nut at the hub like most IRS cars. No rattle gun in use here, these need to be torqued to spec.

14.) With the lowers and the axles in place, it's really starting to look like something! On to the uppers...

15.) The Heidt's setup uses heim joint ends throughout, so no binding, and alignment will be adjustable across the board to meet whatever your needs are, be it aggressive road course racing or just cruising the backroads. The shown offset bushings are used in the upper link mounting points.

16.) Attach the upper link to the inner mounting point first, and adjust it to a halfway neutral position with the locknuts left loose. This will make attaching the hub and spindle a breeze.

17.) Attach the upper link to the spindle. Again, don't forget the offset bushings, these will allow everything to move freely with no binding.

18.) Getting down to it! Next up are the shocks. Heidt's recommends a liberal application of anti-seize to the coil spring adjuster threads. This only makes your life easier when making ride height changes once you're finished up.

19.) Once you have your coilovers assembled, bolt them in place.

20.) Assembled and looking killer!

21.) The forward struts helps with any kind of rotational movement and help act as a traction bar of sorts, if you will. Installation is fairly simple. Locate and drill the holes to the crossmember, bolt it in place, and bolt the struts in.

22.) All finished! Heidt's provides alignment specs for this setup with their instructions, so your local tire and wheel specialist should be able to get it squared up with no problem whatsoever.