advice on a bb in a 66 dart

Hey I see the pics so I know its possible but what can anyone tell me about putting a bb in my dart I want to run my 833 no pwr steering. Is there a physical size difference between the 383 and 440 or just bore and stroke? In someones pics I saw exhaust manifolds do they fit better than hacking up my inner fenders? any advice would be greatly appreciated. What about the handling is it aweful with a 440? thx