Andrew.......The rear end is still the original 2.83. All I've done to it is change the pinion seal. The transmission was custom built by Phoenix Transmissions in Weatherford Texas. http://www.phoenixtrans.com
They custom build each tranny. This one has a shift kit, heavier bands, larger drums, some internal updates to bring it up to date. I can't remember everything they did. You can check out their website listed above. They are known as being the best in the business, or at least in this area. They ship worldwide and do alot of business. Anyway, thanks for the look and compliments