As you can see in the photos, the welds are all accomplished by way of the proven Heliarc process. The axletubes are firmly planted in the center section, and are not only welded around the circumference of the tube, they are also welded horizontally to the center section (twice per side). In the end, no short cuts are taken. Included in the housing package is a set of unique internal gussets. As shown in the photos, the gussets are triangulated and prevent the center section from moving fore and aft. As mentioned previously, the hypoid action of every ring-and-pinion (Ford or otherwise) will always try to force the ring gear out the back of the housing or carrier. The more power available and the better the traction, the more aggressive the fore-aft action. With the gussets in place, this fore-aft movement isn't possible. The result is more power to the ground and significantly improved ring gear life.
Another factor influencing gear life is the shape of the housing internals. By carefully laying out the design, Bickel has been able to limit the amount of oil drain back away from the ring and pinion. Why is this needed? Simple. At race speeds (say 9,000 rpm), there simply isn't any rear axle lube on the ring gear in a stock rear axle assembly. The design of the fabricated housing is conducive to maintaining lubricant on the ring-and-pinion assembly.
Jerry Bickel Race Cars offers two different basic versions of the fabricated housing: One is designed around conventional axles, while the other is designed for use with full-floating axles. By using a floater housing, the axles never see any bending loads (they only see torsional loading). The bending loads are carried by the spindle and housing. Typically, a full floating housing is used in extreme horsepower combinations, such as a nitrous or Pro Mod application.
What's the difference in weight between a fabricated sheetmetal housing and a braced 9-inch Ford? Bickel (who builds both designs) points out that a typical fabricated housing for a Pro Stock application will tip the scales at approximately 41 pounds. Meanwhile, a fully reworked, similar dimension Ford 9-inch housing (with all of the surgery necessary to make it live) will weigh in at 46 or more pounds. When comparing a full width, bolt-in housing such as the Fab 9, Chris Alston reports weight savings of anywhere from 10 to 15 pounds, depending upon the application. Of course, this weight loss is effectively unsprung, which means the shock absorbers actually have less mass to control. In turn, this can mean more performance gains than just a simple weight loss. As you can see, the sheetmetal housing wins from both the strength and weight perspective.
So how long does it take to build a housing? Typically, a fabricated housing from Bickel requires at least a week of fabrication time. Meanwhile, a conventionally braced Ford housing can absorb a considerable amount of shop time, as well. Not counting the search for a decent (non-rusted, non-bent) core, then factoring in the time it takes to clean it, a chassis builder can spend anywhere from 16 to 20 hours (or more ) in the rework. Obviously, the difference in shop time is reflected in the price. Typically, shops charge in the range of $1,600 for a completely braced Ford housing. A fabricated sheetmetal housing from Jerry Bickel Race Cars can cost $2,800, while a Fab 9 housing from Chassisworks ranges in price from just over $300 to $1,000 (both in mild steel), depending upon the application.
Aside from the space-age looks and lightweight, a sheetmetal housing will invariably feature tubes, which cannot be twisted out of the housing. They're straighter than even the best modified housing and finally, the housings are significantly stronger than a modified FoMoCo housing. Best of all, there isn't a stock Ford part in the thing. And your Chevy certainly won't reject it!