Third member, housing, suspension
What do you want in a race car rear end?
1 strength
2 light weight
3 low rotating weight
For strength, we went with a 4130 molly Fab 9 housing from Chassisworks. To fill it and for light rotating and static weight we consulted with our friends at Mark Williams Enterprises, and settled on a 3.182 carrier bearing diameter thru bolt aluminum center section, filled it with an aluminum spool, a lightened 9310 steel 4.10 ratio large pinion Richmond gear, along with a heavy duty ball bearing pinion support. 40 spline Superlight axles, along with their 5 year breakage warrantee, round out the package. I must say, short of titanium, there is no better rear end assembly on the planet, for strength, and weight reduction. The complete rear end, including the Wilwood rear discs, tips the scales at a measly 118 lbs, or a reduction of almost 100 pounds of static weight, and a whole bunch of rotating weight. There is ET here, and every advantage needs to be taken to get this brick nosed GS into the 8 second zone. With just a Stage 2 494 motor.
When I questioned the use of aluminum to the MW rep, he again verified the estimate car weight when finished (2700 lbs) and then chuckled... "That is exactly the same rear that virtually every pro stocker used, before the advent of titanium rear end parts, and those cars, while being 350 lbs lighter, had upwards of 1200 HP, and a clutch, and parts breakage was never an issue".
Good enough for me.
The major drawback of this setup? You guessed it.... price. Let's just say you could build a decent 455 for what this deal costs. But you get what you pay for, check it out!
That is a standard 12 bolt carrier bearing, being dwarfed by the 3.182 bearings on the spool. The spool weighs 4.5 lbs.
Another view comparing the races. Big bearings equal high load capacity, and more meat in the critical area of the spool around the 40 spline axles.
specially lightened ring gear
measuring up the pinion depth with the special tool, to determine shim thickness.
Always double check and inspection mark your torque on the ring gear bolts.
A 3.052 dia standard 9" center section is used to hold the adapters for installing the ends. With the adapters in both the housing bores, held in place by the caps, the mock up center section is then bolted, with the correct thickness gasket, in the housing, the 2" precision ground steel bar, which over 3 feet long, is then slid into the center section adapters, and then the adapter for the housing end is slid on, which insures perfect alignment of the housing ends. The assembly is held in place by clamps, tack and then finished welded. We use only the approved TIG welding method for this operation, on any housing. This is also the way that you correctly eliminate the "C" clips on a GM 12 bolt rear end.
This picture was actually of a mock up, the ends were installed after all the brackets and back brace were finish welded.