| huh? they're is no turning it into a "6-speed". By itself it has 4 forward gears, and that's all. 1,2,3,4(od). The only way to have the split gearing is through a gear vendors unit bolted on the back(which all together would way a ton, and require total re-working of the trans/ds tunnel to fit it) and that would make it an 8-speed.
There are companies that offer a manual vb for the 4l80e, thus giving you non-computer control of it, but they are full-manual control, thus it will not up or down shift on it's own it will be in the gear you select via the shifter. - PATC offers this, I don't know of any others, but I've never looked that much, as I wouldn't go through the work of putting one in a 3rdgen, and the only one I have operates manual via a relay/micro switch/shifter that I built.(to cheap to spend $1400 on the T-Com, and manual control is fine for what it's going in) | 
