I built this cold air box for fun. It has a K&N 11" by 2 5/16" ring element and an 11" breather type lid. It is rated at 1050 cfm at 1.5 inches of H2O which is plenty for my little windsor.
It has the following features that I really like:
1) Gets cold air to the carb ( 1% HP gain per 11 F decrease in intake air temp)
2) It is very easy to take on and off, just remove the air filter and it comes off.
3) It does not interfere with anything else on the engine like the fuel lines and throttle linkage.
4) It was so easy to fabricate, even I could make it
