Cracking throught the carb

[Bob]

About a month ago my 74 started cracking up through the cab on the passenger side.
I did verify that the cam/valves are working properly. A friend told me they had the same problem but it was in the ignition sytem. After about 900 rpm it starts cracking. It's not really a backfire.
It's a 400, 4bbl. Any suggestions?

Thanks
Bob

Again, Thanks Troy. You the Man!

[RD]

spark plug wires may be toast.

[Chryco Psycho]

could be a valve problem , or could just be too lean , or maybe you have a leak at th eexhaust manifold if it is just a noise you hear 

[Charger_Fan]

...Flat cam...timing too far advanced...or your little brother dropped popcorn in the carb trying to be funny.

[Bob]

There was a loss of power because of this.
Other than inspecting the cap/rotor and wires I did remove the valve covers and crank and measured the travel of each valve. I then removed the rockers to see if any valves would fall over but all seemed well. I think I will try a good tune-up first. Cheapest way first. The timing was right on the money.
Will keep you posted.
Thanks

[Chryco Psycho]

have you done a compression test ?

[Bob]

That's next when i get time.

[Bob]

A little old, 2005, but it was the cam.

[Ghoste]

It's good to hear that you finally have it nailed. 

[Bob]

And it runs great. Now if I can just get the pulley thing figured out.