Back when we were using that axle in dirt track race cars about 30 years ago, it was pretty common to keep two center housings around, one with a 4.56 gear, and another with a 4.11. On the "short" 1/4 mile tracks which measured 1320 feet around the outside wall, we used the 4.56. A "long" 1/4 mile, measured around the infield, needed a higher gear, so we would swap for the 4.11.
If you want to swap only the ring and pinion, you'll also need the ring gear/spider gear carrier housing, which has a different side-to-side spacing than the 4.56. Leave the 4,11 as a complete assembly, pull both axles, and swap the whole center chunk. It's less than an hour's work. If you try to mix & match parts, you're almost guaranteed to get a gear howl, as the tooth contact pattern is extremely difficult to match up once a set of used gears have their running relationship disturbed.
Jerry
Edit: If you have managed to find a 4.11 axle, you should also consider buying a Powerball lottery ticket. The odds of scoring either one are astronomical, since the 4.11 was only used behind certain 3/4 ton rigs with an automatic transmission. It's scarce as hens' teeth!
Jerry
Last edited by Hotrod Lincoln; 12/29/2008 3:01 AM.
