Been around a lot of engines most of my life, gas/diesel. I agree with Dale. Fuel, air, spark equals combustion. After all of the new components in the rebuild I don't see you mentioning that the head or block was tested. A cracked block or cracked head will not allow a sealed combustion chamber. A $30 tool will tell you if you have a sealed combustion chamber. I would highly recommend you buy one and test your motor.
