4L60E TCC lock up at 3rd in OD

[V8fan]

Hello everyone
I used search and looks like I don't know correct words to ask it right
I wanna use TCC lock up not only in final gear but into both 3 and 4 -3rd TCC on ,unlocks TCC -shift to 4th and locks again into OD mode without touching lever from 3th to OD
Can it be done with OEM 1999 black box PCM?

[RDF1]

Im pretty sure its hard coded to unlock during a shift. I havent messed with a black box in a long time tho.
Look into a "0411" "P01" PCM swap.

[Fast4.7]

Enable shift lock to keep the converter locked, that being said a stock 4L60E will not like that. Beyond that it should lock the TCC in 3rd stock. My 97 Express L31 with a 4L60E locked the TCC in 3rd and 4th stock and would WOT lock at 75 mph.

[V8fan]

Enable shift lock to keep the converter locked, that being said a stock 4L60E will not like that. Beyond that it should lock the TCC in 3rd stock. My 97 Express L31 with a 4L60E locked the TCC in 3rd and 4th stock and would WOT lock at 75 mph.

I think it will be very harsh shift for me since I drilled 0.120 4th feed and installed sonnax super servo with blocked 3-4 accumulator
I mean if I rise 3 to 4 changing gear speed above 3rd TCC lock speed will it lock it in OD or its forbidden into PCM firmware ?

Im pretty sure its hard coded to unlock during a shift. I havent messed with a black box in a long time tho.
Look into a "0411" "P01" PCM swap.

I have P01 and wiring -but too lazy to finish wiring for my setup )
Wanna try it with black box

[V8fan]

Tested it
If I rise 3-4 speed and lowering 3 TCC Lock speed the tranny locked at 3th in OD
But TCC lock is very slow -it cant release TC clutch in time and hash bump happens every time nevertheless TCC lock during shift is disabled
Where can I change TCC lock timing to let it release more early ?