Yes, it could be an ECM issue. Could be a genuine load issue. Could be something is tripping a defuel table. Could be a tune issue.
You refuse to discuss setup for purposes of diagnosis. You can't expect people here to blindly stab in the dark. If you've got a secret squirrel setup, go talk to the squirrel you bought it from. If you want help, start answering questions.
Hook up a scan tool and drive around and try to get 100% engine load.. If you still cant achieve 100%, then start ruling out the tst, ez, and smarty. Take one off at a time..
Scheid stage 2 cam, fly cut piston top fuel coated, balance bottom end, pdi manifold electric water pump, electric fan's. ported on exhaust side in intake best that it could with out cutting intake off. Truck ran smarty TNT-R, TST & EZ last time i talked was around previous on in Convintion TN. Has twin CP3 S400 charger.I was thinking about buying engine last winter.
Hope this helps guys this is all that i can remmber from when i was going to purchase the engine instead of building mine.
Should it hit 100% load on the street with stock tuning?
weird.i know there was ecm load issues in the 03-04 ecm. your truck looks like a 06 and up so that problem to my knowledge is obsolete to your ecm from what i understand. assuming your running a smarty, try and re upload the program from your computer and then to the truck. fixed my issues in my 03