Fatman Fabrications - Bolt In Fatman's IFS - Tech

As most GM fans know, Chevy and GMC stepped up to the plate and hit one out of the park by going for a well-designed, tough front suspension in their 1/2-ton trucks in '62. (We won't mention the short-lived and more than a little embarrassing torsion bar fronts just prior to this.) This same basic IFS, with unequal-length A-arms, a substantial cross-shaft, and ball joints, was used until '87 before being substantially changed. It has excellent geometry, little tendency to bumpsteer, and wears like iron. The paradox is that while it was a great suspension, for quite some time people have looked for any number of ways to replace it-with good reason.

Among the reasons is that until '71, GM did not offer disc brakes. Drum brakes just don't cut it unless you have a very light car or you don't plan on driving normal modern speeds. Another reason is that the design of the crossmember does not allow a really good front drop. Get it down a little too far or have a little too soft a spring and every pebble in the road becomes something to drag the crossmember or inner ends of the A-arms on. Yet another would be that for a serious custom, the factory-stamped parts are too bulky and not exactly a fashion statement. Finally, right from the factory, you are limited by the bulky crossmember as to the space for headers.

Many replace the original front suspension with a Mustang II variation, but there's always been debate about this. Some still do not understand that most parts of these suspensions are no longer Mustang II at all, but aftermarket upgrades, modifications, and reproductions. They miss that the original Mustang II brakes are almost never used because they are too small for full-sized vehicles. Big brake upgrades are standard now. They also miss the fact that Mustang II spindles were used in vehicles up to the size of a full-sized Ford Galaxy-often because they are forged spindles and much stronger for their size than the cast or nodular spindles they replace.

Kits like the Fatman Fabrications' bolt-in unit we'll be looking at here are certainly strong enough to be used in a 1/2-ton pickup truck and have adequate stopping power. They also have the advantage of being bolt-in. Some like weld-ins better, especially for a completed truck (where a lot of welding and re-work is not appreciated), or for someone who wants to do a quality upgrade without welding. (Not everyone is a great welder.)

You'll be impressed by the simplicity of this installation. There are always a hundred different ways such kits can be difficult to install or poorly designed, but the Fatman people appear to have nailed this one down quite well. Things fit, holes aligned, and it all went together like a precision puzzle.

Another attractive thing about the Fatman kits is their new cast-stainless A-arms. Surprisingly, they are supplied for the same price as fabricated tube arms available elsewhere. Volume is the secret; one pair is pretty expensive, but after the design and tooling are completed, a thousand pairs gets much less pricey. Add to that the rather clever scheme of fabricating one basic arm that will suit all the many Fatman kits, along with relatively inexpensive arm inserts to accommodate spring and shock variations and models, and you have a way to get stainless arms at a great price.

Finally, there is one important issue that really needs addressing. There are several places where large bolts are installed inside steel sleeves of one sort or another. Experience has taught that if you ever want to get the bolts in and out-especially after they've seen any weather-you'll make sure they are liberally coated with anti-seize. The Fatman kit contains several large, long bolts that really require the application of anti-seize because they are high-strength stainless steel. (No, regular mild stainless cannot safely be used for suspension.) If you fail to grease these up with plenty of anti-seize, you will at least damage the hardware, and at worst get it stuck in the bores so thoroughly you are unlikely to ever get it out again. All stainless, Nylok nuts, and hardware installed in sleeves or tubes require anti-seize to avoid serious problems.