I would buy the dart for reasons above + others, I have a .825 base circle cam in my 434 against my better wishes, go with the raised cam. Also if you do buy world sonic the block before you machine it. The first one I bought was .080 thick in #3 bore, I didnt discover this until I had water in #3 hole. It took me 5 months of stress to get a new block. Another friend of mine just had his new world block bored for 55mm roller cam bearings, they broke through into the water jacket, according to world the race block should accept 60mm roller cam bearings. Bottom line is just be careful if you buy a world block. In my opinion there customer sevice is less than poor. I would only buy chevrolet or dart if given the choice.
Bryan