Silverado, 305 after sitting for 2-3 days very hard to start. on 1998 Chevrolet 1500 Pickup

It's almost like the fuel has evaporated or drained back to tank......Crank on her sometimes 10 -12 times then she fires up. Pump & tank new. Can hear pump running also

Fuel spider assembly most likely, have fuel pressure tested, key on then off to see if fuel pressure drops off quickly. If you have to remove the plenum to fix this, replace the assembly!