mine is also a 1058. I have tried every trans tune from stock to whatever, will not lock in 2nd or 3rd with a 4wd boost launch. I've finally got it to lock in 4th and 5th, wasn't doing that either from time to time.
As far as an engine tune, running twins I am not even sure it'll run with a stock tune, but I may try today. I have tried several of Robs tunes and they all have the same lockup problem. I have put all the defuel back in also, no affect. I have tried three different operating systems, no affect. I'm confident in his tuning. He has seen these issues also, said the 1058 is one of the most consistent with having the lockup issues when racing, but others are as well.
They will also unlock at a downshift and not re-lock until 4th and 5th gear. This would be like cruising at 50 mph, fifth gear, converter locked. Go wot to pass, downshifts to 4th and unlocks the converter until some period into 5th gear again, even though I've tried lowering the lock applys for 4th (and lower gears). If you prevent downshifting it'll hold lock all the time. Go to tow/haul in 2nd and then go wot at 16-20 mph before it upshifts to third and it won't downshift to first and stays locked through all gear. Check out a datalog and see the several tenths in et this gains, at least on my truck. Would love to get this figured out.
EDIT: Went and loaded a 50 hp tow tune (closest thing to stock I had for my new OS). Did a full throttle launch and it still would not lock the converter in 2nd and 3rd gear, even with wot lockup commanded at 18 mph. Then I loaded the stock Allison tcm tune in with the same tow tune, and same thing, no 2nd or 3rd gear lock under wot from a standing start.
So again, three different operating systems, mild 50 hp to full blown twin race tune, and everything from bone stock tcm tuning to fully modded by me tcm tuning, and the results are always the same; no wot lock in 2nd and 3rd gear when drag racing. Locks perfectly at any throttle less than 100% tp. I'm really leaning towards the converter as much of the issue (1058 in my case) as with the power in the toilet on that tow tune and full defuel it still won't lock up.
Jody