To do that, you would probably want to set it up to be manually shifted in and out of overdrive. That would allow for gear splitting in all gears. I would have to look at the ratios and perhaps do a little math to figure out the actual pattern one would use, but one could simply do 1rst, 1rst/over, 2nd, 2nd/over, 3rd, 3rd/over to get 6 gears. The pattern may not work out that way, though, as it is dependent on what the actual ratios are.
Personally, mine is left to work as it would in the oem application, other than the addition of a switch for when the overdrive is locked out and not being used. That pretty much eliminates the use of 1rst/over, as hitting 28 mph in 1rst gear before it engages would wind things up a little too tight. Usually, I'll only let it split 2nd gear, then shift directly into 3rd over.
