I changed the ecm and still no start,changed distributor, cap, rotor,ignition,

why did you replace all that?icm and pick-up-coil you left out.there is a way to test for things,before you start dumping money in the truck,that could be still in your pocket.It is best to test your old parts first.i would keep all the parts you replaced,as spares.if you are getting power to the input side of the coil,with switch on,and then you have no spark to plugs, while cranking,icm is suspect.good luck.