1976 Z case questions

[sonic]

Hi all ..
Want to do some track racing next year and have som questions regarding this box ..
1200 Pound car , 220 HK 2,6 ltr engine .. What kind of mods /improvemensts do I have to perform to this box .. its a 1976 Z box with 3,87 final drive ..
Know a superdiff with 4 spider gears would be nice , but there so many offers out there high to low price ??

Rgs
Erich

[Bruce]

Most guys would want to replace the fine tooth gears with coarse tooth Bus gears.  The Bus gears have their synchro cones electron beam welded to their gears.  The gears from a 72-75 Bus are what you're looking for.  72-74 has an extra tall 0.82:1 top gear.  A 0.89 comes from a 75 only gearbox.

Get some Type 181 or Type 182 flanges.  They use the larger Bus size CV joints.

[sonic]

Thanx Bruce , help a lot ..

Rgs