265 CID: 1955-1957
BORE: STROKE: DECK HEIGHT: DECK CLEARANCE: COMPRESSION HEIGHT: ROD LENGTH: ROD RATIO: ROD JOURNAL DIA.: MAIN JOURNAL DIA.: MAIN BEARING BORE DIA.:			3.750 3.000 9.025 0.025 1.800 5.700 1.900 2.000 2.300 2.491
BORE vs STROKE
BORE	STROKE	CRANKSHAFT	CID/Liter
3.750 3.750 3.750 3.750 3.750	3.000 3.100 3.250 3.480 3.750	265/283/302 262 307/327 267/305/350 400	265.0/4.3 273.9/4.4 287.1/4.7 307.4/5.0 331.3/5.4

Introduced in 1955 it is the first small-block. The 265-CID blocks had no oil filter nor provision for one. On early 265-CID blocks oil was feed to the lifter galleries through two holes in the rear camshaft bearing. Early blocks will stand boring 0.125-inch. One block produced around 1957 had slightly thicker cylinder walls, It can be identified by the letter "C" at the end of the engine serial number.