Truth Lewis

I had my 6l80e transmission upgraded for all its defects and had it beefed up for 1000 hp build installed a hays twister 1000 hp torque converter also did my long tube headers also in the future so bolted it in started ran fine sounded great started twice cool. So i go to put my truck in nutrual so i can install my drive shaft so i can see if she moves i install the drive shaft and get in my truck put it in park and try to start it nothing just click i look down at my dash no gear indication. Whats the possible reason its not running.