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Small Block and Big Block Engine Bore and Stroke Chart

Bore & Stroke Chart
Small Block Engine
EngineYearsBore DiameterStrokeRod LengthMain Bearing DiameterRod Bearing DiameterMain CapsJournal SizeNotes
262 1975-76 3.671 3.10 5.7 2.45 2.10 2-bolt Medium  
265 1955-56 3.75 3.00 5.7 2.30 2.10 2-bolt Small  
265 1994 3.736 3.00 5.7 2.45 2.10 2-bolt Medium  
267 1979-81 3.50 3.48 5.7 2.45 2.10 2-bolt Medium  
283 1957-97 3.875 3.00 5.7 2.30 2.00 2-bolt Small  
293 1999- 3.780 3.27 5.7 2.30 2.10 2-bolt Medium "LR4" 4.8 Liter Vortec
302 1967 4.001 3.00 5.7 2.30 2.00 2-bolt Small  
302 1968-69 4.001 3.00 5.7 2.45 2.10 4-bolt Medium  
305 1986-97 3.736 3.48 5.7 2.45 2.10 2-bolt Medium 1-piece.
305 1976-86 3.736 3.48 5.7 2.45 2.10 2-bolt Medium 2-piece
307 1968-73 3.875 3.25 5.7 2.45 2.10 2-bolt Medium  
325 1999- 3.78 3.62 5.7 2.45 2.10 2-bolt Medium "LM7" 5.3 liter Vortec
327 1962-67 4.001 3.25 5.7 2.30 2.00 2-bolt Small  
327 1968-69 4.001 3.25 5.7 2.45 2.10 2-bolt Medium  
350 1967-85 4.001 3.48 5.7 2.45 2.10 2/4-bolt Medium 2-piece
350 1986-95 4.001 3.48 5.7 2.45 2.10 2/4-bolt Medium 1-piece. TBI injection
350 1996-00 4.00 3.48 5.7 2.45 2.10   Medium Vortec 350
350 1989-95 3.90 3.66 5.74 2.45 2.10 4-bolt Medium "LT5" in ZR1 Corvette 32 Valve DOHC
350 1997- 3.90 3.62 6.098 2.45 2.10 4-bolt Medium Gen 3 " LS1" makes 346 cubic inch
364 1999- 4.00 3.62 5.7 2.45 2.10 4-bolt Medium "LQ4" 6.0 Liter Vortec
377 400 Block 4.155 3.4 5.7 or 6 2.45 2.10 2/4-bolt Medium Must use main bearing spacer.
383 350 Block 4.03 3.75 5.565,
5.7,
or 6
2.45 2.10 2/4-bolt Medium 400 mains cut to 350 size
400 1970-72 4.125 3.75 5.565 2.65 2.10 4-bolt Large  
400 1973-80 4.125 3.75 5.565 2.65 2.10 2-bolt Large  

 

Big Block Engine
EngineYearsBore DiameterStrokeRod LengthMain Bearing DiameterRod Bearing DiameterMain CapsJournal SizeNotes
366T 1968-90 3.935 3.76 6.135 2.7495 2.7488 2.20 4-bolt Standard  
396 1965-69 4.096 3.76 6.135 2.7495-
2.7488
2.20 2/4-bolt Standard  
402 1970-72 4.125 3.76 6.135 2.7495-
2.7488
2.20 2/4-bolt Standard  
427 1969-69 4.25 3.76 6.135 2.7495-
2.7488
2.20 2/4-bolt Standard  
427T 1968-85 4.25 3.76 6.135 2.7495-
2.7488
2.20 2/4-bolt Standard Tall Deck
454 1970-90 4.25 4 6.135 2.7495-
2.7488
2.20 2/4-bolt Standard  
454 1990-up 4.25 4 6.135 2.7495-
2.7488
2.20 2/4-bolt Standard  
502 1996-up 4.446 4 6.135 2.7495-
2.7488
2.20 4-bolt Standard  

 

  1. two combinations were not listed. A 4oo block with a 3" stroke displaces 321 cu. in. and with a 3.25: stroke displaces 348 cu. in. My build has a 0.030" overbore for a bore of 4.155" with a 327 stroke and it displaces 353 cu.inch.

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