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Frontal Lobotomy Part II

Puttin the Sutures in on the RB's IFS Retrofit at Temecula Rods & Customs

Feb 3, 2003

Hopefully you were able to catch our first installment on the frontend rehab of a '54 Chevy performed by Temecula Rods & Customs (TR&C). It showed the rare, but not uncommon, situation where someone has gotten in over their head--lacking fabrication/engineering skills and over-eagerness can result in a scary front suspension setup. Part I of "Frontal Lobotomy" wrapped up with the reconstruction of the Chevy's framerails and the beginning install of the new RB's Obsolete Automotive MII crossmember. Here we'll stitch things up with the final welding of the crossmember components, as well as with all of the modifications that were required to utilize an airbag system custom tailored by TR&C.

The installation of the crossmember was a breeze; it was the rebuilding of the rails that was the most time consuming. But once that was done, things went smoothly, especially with the aid of RB's frame template, which allowed everything to go in square and true. The crossmember kit is meant to be a bolt-in deal, but since a lot of modifying was done (for airbag and steering clearance, etc.), the hats and center piece were welded to the frame once everything was set up properly. To further maintain the frame's squareness, small sections were welded at a time to keep warping, if any, to a minimum. The strut rod mounts, though, were not welded in just in case the control arms are ever swapped out for tubular ones.

In addition to the frontend, RB's also supplied a Serious Hardware power brake conversion kit (necessary for the disc brake upgrade), trans mount K-member, and Column Saver in order to use the stock '54 column with the power rack-and-pinion (each mated with Flaming River steering joints). For the brake kit, which bolts in where the stock single-reservoir master cylinder is located, the driver side floorpan directly above had to be raised slightly for clearance. And since the fluid chambers ended up directly below the seat, the decision was made to use a remote-fill reservoir that will be mounted on the firewall. The K-member went in without incident, and the Column Saver literally saved the day, allowing the guys to focus on other areas rather than making them deal with fabricating a custom-made bushing for the stock '54 column. (RB's manufactures them in a variety of different diameters, so if you're running a rack or different type of steering box that requires U-joints but would like to keep the column you've got, now you have a solution.)

I'll quickly get into the modifications, and then let the photos do the rest of the talking for the story. Refreshing your memory, the Serious Hardware IFS kit is basic in nature, designed to use OE Mustang II upper and lower control arms, spindles, and even strut rods. First off, the stock spindles were swapped for Heidt's dropped spindles (an option from RB's) for reasons of ultimate lowness. The outside portion of the spring/shock towers--or hats--were replaced with new pieces of metal (allowing for better airbag clearance), while the lower control arm's coil pocket was alleviated in order to fit the bag mounting plate; the top of the bag now mounts to a removable plate that fits flush into the hat. The frame itself had to be notched on the left for the rack's U-joint to rotate without binding, and a Flaming River stabilizer was welded right above. Finally, the strut rods were fit with lower shock mounts as far forward as possible to utilize full travel of the shocks.

Okay, so it took some time, but now the '54 has an undeniably solid front suspension with no "hokiness" or dangerous traits. What the TR&C boys--Brian, Lane, and Sal--have done is taken an accident waiting to happen and created a solid front suspension with modern brakes and steering. If you've learned anything from this series, hopefully it's the fact that paying more for something done right the first time is a lot better than paying more to have a cheap job fixed later. Having a shop like Temecula Rods & Customs install a proven product like an RB's Obsolete kit is a total win-win situation.


Where we left off, Brian and the boys at Temecula Rods & Customs had rehabilitated the Chevy's framerails and tacked the crossmember components in place. Since then, all modifications were made for proper airbag and steering clearance. The whole unit has now been fully welded to the frame. If you're familiar with a typical MII spring hat, you'll notice in this photo that the side supports are minimal--they're new sections made from steel to allow the airbag to expand without coming in contact. The 1/2-inch lip on the framerail was trimmed for the same reason.

Looking up just a bit, you can see the plate Brian made for the upper bag mount. This piece attaches to the hat with three Grade 8 Allen bolts.

The bag attaches with standard Hex bolts. The air line runs through the modified ex-upper shock mount. This shot also illustrates how nicely the framerail was reconstructed.

With the stock MII spindles, the tie rods would hit the frame before the suspension was completely compressed; the addition of the Heidt's dropped spindles alleviated that. Still, the frame was clearanced for safe measures.

For the lower bag mount, the bottom control arm was slightly modified in the spring pocket area and holes were drilled to attach the mount front and rear.

The actual bag mounts are accessible from beneath the control arm, so if need be, they can be removed without removing the mount itself.

While this shouldn't be the case in each situation, because the stock column was retained, a notch was necessary in the frame for U-joint clearance. Binding steering components is definitely not a good thing.

RB's also supplied the motor mounts, which weld directly to the inside of each spring hat. You can see things are starting to look more like a real frame at this point.

With airbag front suspensions, shock mounts can sometimes turn out to be a real pain.

Fortunately, the use of strut rods afforded a lower mount location, while the open framerail behind the crossmember was the obvious locale of choice for the uppers. Keep in mind that mounting as close to the A-arm as possible is critical to appropriate shock travel.

As mentioned before, the stock '54 steering column was retained. Since it was originally permanently "fixed" to the stock box, cutting it loose left it dangling through the firewall. Brian fab'd a pocketed collar that was welded to the column and then bolted to the firewall, making column removal easier if ever necessary

An RB's Column Saver was used directly below, and a Flaming River 3/4-inch to 3/4-inch/36-spline U-joint linked everything to a 3/4-inch double-D shaft.

Although a tranny crossmember for the TH350 was already existent, it was fairly crude, so TR&C opted to update things with RB's Serious Hardware K-member. The rectangular steel unit bolted in place perfectly, ultimately locating the tranny just as nicely.

Since the new IFS uses disc brakes, the old single-chamber master cylinder would not suffice. RB's offered up their power conversion kit as the solution. If you look closely, you'll notice that the actual master cylinder shown is sans fluid chamber--Brian decided a remote-fill suited the tight situation under the floor best. Also note that the floorpan directly above the booster and master was slightly raised to provide a little added elbowroom.

A plate with three tapped holes is used to mount the master/booster to the frame, while the pedal pivots off a threaded bung (with a square-tube brace going back to the booster bracket) welded to the frame just below the firewall kick up.

A slight angle in the pedal pivot required the pedal itself to be bent slightly so that it came through the firewall straight.

Brian's airbag bracketry is about as clever a design as you'll find. Not only did he eliminate the common tubing top mount (which can move around if not secured right), but made it so that if ever necessary, removal wouldn't be a hassle (both upper and lower brackets are bolt-in).

The Heidt's dropped spindles alleviated any tie rod interference with the frame, but the issue of 14-inch wheels not fitting was still an issue. Not only do the tie-rod ends rub, but the wheels won't even fit over the calipers. A set of 15-inchers will be ordered from Wheel Vintiques.

With the shorty shocks installed, you can see that the angle is just right and that there will be more than a sufficient amount of travel. Had the shocks been mounted closer to the strut rod frame bracket, travel would have been greatly reduced, plus the angle would have decreased, making them less efficient.

Which frontend would you rather have riding under your custom?

The '54 gained the added performance of disc brakes and rack-and-pinion steering, as well as the assuredness of a proper suspension system, including geometry.


RB's Obsolete Automotive
Edmonds, WA 98026
Temecula Rods & Customs
Temecula, CA 92590

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