i have an 86 z28 with a 305 tpi. i parked it for the winter, i put a bottle of stabil in the tank before i stored it. over the winter i put a bigger throttle body and cut out the caty, and i dont have an egr valve. a few days ago i started it up and it ran fine(except it wouldnt idle) and today it just wouldnt start and i keeps fouling out the plugs, and i cant figure it out

Is it fowling all plugs are just specific ones (like cylinders 6 & 8)? Pull the vacuum line off the fuel pressure regulator and see if fuel dribbles out. The pressure regulator diaphram may have ruptured allowing raw fuel to be sucked into the motor.