It could also be possible that the engine is stuck, like a hydrostatic lock. Check to see if you can turn the engine over by hand or with a bar/screwdriver in the flywheel teeth. Carb could flood out & fill up the cylinders, in this instance you don't want it to try to start as it will likely break something.
Fred

1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine