Allison Shift Kit Jr in stock transmission?

[Picklito]

07 LBZ 6-speed. 156k miles, no tune yet, all stock, no issues other than the stock slow/sloppy shifts. If I install JUST the Allison Jr kit for now, what will I get?

[Picklito]

I ordered the kit. Will report.

[Picklito]

Installed this week. Did it on a lift which was helpful. Along with the installation I changed both internal and external filters and cleaned the pan and magnets. At 165k there was VERY little schmutz in there. I had read to buy 3g of ATF for the installation, and it took all but one pint. The included instructions are minimal. For example, they didn't even include a diagram of which bolts to remove to pull the valve body. Instead, the instructions start with the valve body already removed and on the bench. Google showed a pic, and it's only 15 of many bolts to get the valve body on the bench, and the rest of the work can be done there. How hard would it be to include that? Since I've done lots of shift kits I'm aware that not all bolts might need to be pulled to get a valve body out, but if this is a person's first time they could be quite confused. You DO end up removing all the valve body bolts eventually, but it's much simpler to remove JUST the correct 15 and get it on the bench before removing the rest. The rest are removed to separate the two halves of the valve body and get to the plate. You then drill two holes to 0.125" and they supply the bit, but it's cheap as heck and almost immediately broke just drilling the thin steel separator plate. Have a REAL 0.125" drill bit as a backup. Then, you change out two shift valves and springs with the ones supplied in the kit. Here, there's a pic, but just cursory notes as to what to look for to make sure you get it right. Again, having done such before I found it simple. Match the pics carefully on reassembly. So, enlarge two holes and swap two valves and reassemble. Took about 20 minutes of bench work then time to reassemble. Overall, it was very simple but, again, I've been there.

The instructions say the computer will need to go through the relearn process, but mine shifted correctly right away, and I didn't do any special driving ritual. The slow, clunky, off-then-on feeling of the clutches releasing then re-engaging is much reduced. It did not make any of the shifts too quick or too firm. I very much did not want a slam like a street-strip car and it's not. Actually, it could be a little firmer, but I'd rather have it be plenty safe for the "process" that the Allison has to go through to prevent tie-up. Does not seem like a risky modification at all. Mine was installed just to get rid of that School Bus feeling and it fixed that. I'm running the LBZ in stock tune and don't plan to add HP, so was not after a power handling increase, and can't comment on that. It seems like a pretty nice improvement for the ~$60 cost of the kit. I hope this was helpful.