richardj23
Newbie
i have a 1998 k2500 with a 5.7 in it, i just put another 5.7 in it out of a 97. The truck runs amazing at idle but when i put it in gear its fine then when i drive it starts backfiring. I have moved the distributer back and fourth moved teeth back and fourth i just cant figure it out. On top of that it no longer reads on the speedometer aswell as it wont shift out until over 4k rpms. everytime i try to adjust timing i just cant seem to get it below 20 spark adv on my scan tool. Do i keep trying to chase the timing part or what could it be? Also the reason of the engine change was the old engine just ran like crap it was not reliable.