318 Poly A engine in a 67 Cuda

I have been researching these engines and it looks like I can build one of these into a 412 or bigger engine. The heads can be ported to near tricked J heads and further on the exhaust side. The block has nearly solid main webs and is not limited to 500-600 safe hp like the 340-360 is. Extra nickel in the cast making them stronger pound for pound. I can build a 412 to 450 plus and throw a torque storm on it and make more power than an La engine bottom end will handle. Then there is the being different cool factor. I just need some details on the fit.
If you do take pic's keep us informed be interesting. Wonder why people don't use these blocks
as a cheap race block for LA builds?