Truck wont start HELP

[69bronco]

hey i got a 72 f250 that wont start and i need some help, im 14 years old. the truck was running then it just stoped running and it won't start. the engine is geting gas,spark,and it has good compression. It has new points and the timing was right. but it wont fire. but went i was working on it tonight i found out that the carb is blowing air out insted of pulling air in. so what would make that happen?? , did the cam or timeing chain break or something? thanks

[Phillyfanfrombirth]

Usually if it just "stops", it is either gas or spark...

If you are getting spark, that means that your timing chain is in tact. I've seen a cam break before... the engine will crank very quickly if that is the case, and you won't get compression out of all of the cylinders.

Now, what you didn't answer...

Engine size?

You say it doesn't "fire", I'd assume that means that it cranks alright though?

Was it running, and just suddenly shut off? Or did it run the last time you tried it, but won't run now?
How's the choke look?

[fiveohpatrol]

do you know you're getting spark to the plugs, or just that the coil is working?

Did you have the distributor out for any reason, and then put it back in 180* out of phase?

Where in Indiana are you located?

[69bronco]

hey thanks for the help, but i found out that the timeing chain and gears wore out so the chain jumped when it deid,i need to learn how to shift better so i dont kill the engine. so i have to order a new chain and gears set and put it on and time it. Then it should run i think.