A good friend of mine owns a Ford Performance workshop that builds arguably Australia's fastest Ford motors. Not long ago, he built a motor for his own street car as an example of what he can build for his customers. He quickly decided that "merely running low 10s" wasn't exciting enough, and built another engine. If you're looking at having Australia's fastest naturally aspirated Cobra, his first combination is the motor for you!!!
351 4V Cleveland with all the good gear - cost to build $25,000.
4V heads that would make many alloy head flow #s look silly.
Ross dome top pistons 12.5:1
Eagle 4340 steel rods
Eagle 4340 steel crankshaft std stroke
Solid roller camshaft 268 degree
Top quality valvetrain ($1,000- valve springs, titanium retainers, roller rockers, guideplates etc, etc)
Revised oiling system
MSD billet distributor
no carb
TFC single plane manifold (Roush type)
It was installed in a 3500lb XY Falcon and ran 10.2 second 1/4 mile @ well over 130mph. It's pretty easy to see that it's a mid 9 second motor for a Cobra.
Selling for
$12,000-...... (For the benefit of any Americans reading this, that's only
$6,500 USD !!!!! 
What's a 9 second motor worth in the States?
He is willing to exchange the high comp pistons for flat-top pistons and a smaller camshaft for pump-gas street driving if the buyer wishes. I kinda hope that it stays exactly as it is though..... a proven combination, and certainly a wild motor for a Cobra!
Reply here, PM or email me if you want further details.