Thought of something else... might be able to wire a relay into the tow/haul circuit that connects with the nitrous solenoid. Adjust the line pressures of the tow/haul tables. Can't say I've seen anyone do it but might be worth looking into.

 

my "tow/haul" button is now the "performance" setting and the trans shifts more aggressively,higher line pressure,etc.this would be good for when you want hit the NAAAAWWWS,i mean nitrous . of course you can tune the trans for nitrous also.talk with your tuner about this, or i can direct you to mine

 

along with a shift kit and corvette servo you could also add the Sonnax heavy duty 2-3 shift valve Sonnax - Aftermarket replacement transmission, torque converter, and high performance automotive parts
With that valve when you are in D3 it applies the overrun clutches in 1st, 2nd, and 3rd gear where the oem valve only applies the overrun in 3rd