Engine - GM Performance Short Block Engines - 350ci Bow Tie Block

From GM Performance - This block, which can be used for 302ci, 327ci, and 350ci engines, is the same as the cast iron Bow Tie bare block P/N 10051183, except that it has a straight nodular 4 bolt main bearing cap. It also features siamesed cylinder walls which could give it a maximum bore of 4.090 inch. It has a crankshaft diameter of 2.45 inch and the newer (1986 and later) one-piece type rear main seal. It replaces the older P/N 366287 4-bolt block, the difference being the one piece rear seal rather than older 2-piece rear main seal. Block weight is 182 lbs.