Why will my Chevy 350 will crank but not start?

no gas no spark no compression no timing dump a cap full of gas down the carb and if it fires you have spark, meaning you have a fuel problem if it doesnt fire, then you have a spark problem. try a new coil or distributor cap, clean or change the points, clean or change the plugs/wires. if that doesnt work you need to check compression. a simple thumb over the spark plug hole works, or use a guage. fixing this problem involves a rebuild. if your distributor cap is on wrong or the shaft is in wrong or the cam is 180 off, these things will all affect the spark of your engine.