318 won't rev past 3000 rpm

Could be any of 20 things.

Ignition Box..........Simple........

I had listed.....

* Fuel Tank inlet tube 'clogged'
* Bad Fuel Pump
* Clogged Fuel Lines
* Timing Chain
* Valve Stuck Open
* Distributor Shaft worn
* Coil defect {cracked or corroded}
* Muffler pipe collapsed. Had that happen to me on a 1971 Chevrolet Malibu 307. The car wouldn't rev over 2500 RPM's.