5.0 to 5.7

[98 gmc 4x4]

is the ecm from the same truck the motor is out of?

No motor is from a different truck then the computer.

 

[badazzbulldog]

see if you can get the vin off the truck the motor is out of you may need to have the ecm flashed to that truck,i just helped another member on here that smoked his ecm and his truck was a 454 that had a 350 put in it and the ecm i got him was flashed using my vin because his truck was a 99 with a 97 service # ecm so all his issues were corrected by programing it to my 97's info it wouldnt run right or shift with the info by his vin#