In the 50's, Aussie backyarders, with no readily available SOHC or DOHC castings, got busy and made there own Twin cam engines using local pushrod I-6 blocks. Krogdahl was just working out a pre-existing idea!
The only issues asside the head castings was making the front cover work.
One partical version had a steel plate on the top of the block, a set of sleaves, and gots some extra capacity out of the engine.
With the 200 engine, it is second only to the prewar MG's, the Triumph 2500 and Nissan Skyline sixes for shallow block depth...it is very shallow, very, very light in the block, and 150 pounds lighter than any of the deep, wide and heavily gusseted EA-AU-BF blocks. With a simple 250 thou deep plate, and some time, you can make the DOHC or SOHC heads fit with ease, You can deal with the water passages by dry decking the block, and using expoxy moter. You can run the distributorless ignition found on EF, AU/BA/BF Falcons, and run any kind of intake manifold you car to.
In my humble opinion, the US/early Aussie 200 block is head and shoulders above the OHC block because its light, and with a little work, it will take the OHC or DOHC Ford head. And offcourse, the DOHC runs a simplex chain, not duplex, and this is even easier to fit up to the earlier 200 engines.
Everyone forgets that the most successfull four cylinder Holby and Raymond Mays Twin Cams were just based on a silly old 957 Anglia/ 1500 Cortina blocks. Racers got 126 hp out of them from just 1558 ccs, and little Lotus Elans and Lotus Cortinas and Twin Cam Escorts did 16 second quarter miles. Lotus Sevensand Europa Sprints did high 14 second quarter miles with these.
As Monte Carlo and other rally competition got hotter, the 4 valve per cylinder BDA twin cam heads were made, using the ohv 1600 and 1800 Ford Escort blocks. Soon, little four cylinder escorts were reving to 10500 rpm, and giving 245 hp from furnace brazed 1600 blocks bored out to 2000 cc's. This great twin cam head eventually found on the Cosworth V8 DFX engine, as both the Ford BDA and V8 were based on the same little block that came out in 1959 Anglias.
Here's how Aussies did it.
http://img73.photobucket.com/albums/v223/xecute/hotsix00.jpg
http://img73.photobucket.com/albums/v223/xecute/hotsix01.jpg
http://img73.photobucket.com/albums/v223/xecute/hotsix02.jpg
http://img73.photobucket.com/albums/v223/xecute/hotsix03.jpg
http://img73.photobucket.com/albums/v223/xecute/hotsix04.jpg
http://img73.photobucket.com/albums/v223/xecute/hotsix05.jpg
http://img73.photobucket.com/albums/v223/xecute/hotsix06.jpg