Pontiac engine boresize's

Cubic Inches Bore (inches) Stroke (inches) Main bearing size (inches)
265 3.75000 3.0000 3.000
287 3.75000 3.2500 2.500
301 4.00000 3.0000 3.000
317 3.93750 3.2500 2.500
326 3.72000 3.7500 3.000
347 3.93750 3.5625 2.623
350 3.88000 3.7500 3.000
370 4.06250 3.5625 2.623
389 4.06250 3.7500 3.000
400 4.12000 3.7500 3.000
421 4.09375 4.0000 3.250
428 4.12000 4.0000 3.250
455 4.15000 4.2100 3.250

Last Updated on 12/31/99
By Fred Teufert