Engine - Block Components - Engine Block

From GM Performance - This cast iron bare block is used in production 4.3-liter V6/90 degree engines. It has 4.00 inch cylinder bores and two-bolt main bearing caps. The lifter valley is machined for roller or flat tappets, and the rear main bearing uses a one-piece seal. This block has fuel pump boss. Technical Notes: This block has the same cylinder wall thickness as current production engines. It has two oil galleries and an open lifter valley; it cannot be converted to V8 style lubrication. Heavy-duty and pre-1986 production crankshaft designed for two piece rear seals can be installed in this block with crankshaft seal adapter P/N 10051118.