L31MaxExpress
I'm Awesome
On mine, going to the 5.3 from the 4.3 the tach was reading low and I had to set something in the tune to output the correct pulses. I can't remember what it is called now.
Found it
https://forum.hptuners.com/showthread.php?15112-V8-tach-output-for-6-cylinder-tachometer
Stock LS tach output is the same as 4 cylinder mode on an aftermarket tach.