Have 1997 silverado p/u real hard to start when cold. acts as though trying to flood. when starts runs rough and misses for 25 30 miles then runs fine, starts fine.
Year : 1997
Make : Chevrolet
Model : silverado
Engine : 5.7
changed plugs wires coil and converters and fuel filter
do you have access to a fuel pressure gauge?
i would rent or buy one. IT sounds like a weak fuel pump, which is very common and all your symptoms point that way.SFI 385 - 430 kPa (56 - 62 psi)