Glen,
The Cleveland is a whole 'nother animal from the Windsors. Clevelands, at least the ones with the 4v (four barrel) heads are high reving, deep breathing powerhouses. Mike is right about them being somewhat rare in the states. Also, parts are somewhat more expensive for the Clevelands. However, it's fairly easy to get 400 or more ponies out of a Cleveland. Clevelands do tend to suffer from some oiling problems, they tend to pump too much
oil up to the heads, causing the main bearings to suffer from
oil starvation, but that can easily be fixed.
The 4v heads have massive intake and exhaust ports that, combined with a free flowing intake manifold and headers, can pump a lot of fuel through the engine. This makes for good top end power, but the engines suffers from a low end lack of torque. This really isn't much of a problem in a lightweight car like the Cobra however. The 2v heads have smaller ports and make better torque, but less HP.
I had a 4v Cleveland in my Cobra and loved it. I once missed a shift and the engine went over 8k rpm without missing a beat!!
The Cleveland is a bit larger than a Windsor, but they fit well in a Cobra and look very cool!
Every now and then, Carcraft magazine will run a good article on Cleveland buildups.
I think you could build a good, strong Cleveland for under $4,000.
Cheers
Jim