[twobjshelbys]

Originally Posted by 427supr

the dart blocks are just built beefier than the stock 351 block.they have thicker decks, thicker bore webbing, siamese bores, priority main oiling, enlarged water jackets and 4 bolt main caps. The dimensions of the dart block are the same as the stock block, so everthing should bolt up when you install. What is nice about the dart block is when you use the 4.125 bore and a 4.000 inch stroke it takes you to the magical 427 number. Actually 428, but close enough. A employee from ford motorsport told me if using a stock block, avoid using anything over a 4.000 stroke. A 4.100 and a 4.170 stroke starts to put a lot of load on the side walls of a stock block.

(4.125/2)**2 * 3.14 * 4.00 * 8 = 427.4325

Dart blocks are definitely beefier than the originals.