Big Block Quick Reference Block Chart.

CHEVROLET BIG BLOCK QUICK REFERENCE "BLOCK CHART"
-	Chevrolet	Chevrolet	Chevrolet	DRCE Block	Chevrolet
-	Gen VI Production Short Deck Big Block	Production 502 Block Prod	Gen V Bow Tie Tall Deck Big Block	-	Mark IV Aluminum ZLI
Part Number	12550307	10237292	24502502	24502572	12370850
Block Material	Cast Iron	Iron	Cast Iron	Cast Iron	Aluminum
Cylinder Wall Type	Non-Siamesed	Siamesed	Siamesed	Siamesed	Siamesed
Cylinder Deck Height	9.800"	9.800"	10.200"	9.300"-9.500	9.800"
Cylinder Bore Range	4.250-4.310"	4.47-4.500"	4.250-4.600"	4.500-4.600"	4.118" to 4.300"
No. Bearing Cap Bolts	4	4	4	4	4
Cap Bolt Orientation	Straight	Straight	Splayed 16°	Splayed	Splayed
Bearing Cap Type	Cast Iron	Cast Iron	8620 Steel	8620 Steel	8620 Steel
Crankshaft Journal Dia.	2.75"	2.75"	2.75"	2.75"	2.75"
Oil Sump Type	wet	wet	wet	dry	wet or dry
Crankshaft Seal Type	1 Piece	1 piece	2 Piece	2 Piece	2 piece
Design Max. Stroke	4.250"	4.600	4.600"	4.600"	4.375"
Weight (lbs. - bare)	N/A	269	273	255	110
Intended Usage	Street	Street - Modified	Profess’l Comp.	Profess’l Comp.	Street - Modified
Fuel Pump Boss	Has Fuel Pump Boss	No Fuel Pump Boss	No Fuel Pump Boss	-	Has Fuel Pump Boss
Non-Standard Parts Required Special Features	Production Style with Fuel Pump Boss & Has 1 Piece Rear Main Seal	This Block is good for 700 H.P.	* Fully Race Prepared MMachining * Valley Head Bold Bosses * Enlarged Main Oil Gallery	* No Head Bolt Holes * No Lifter Holes * Can be machined to 9.000 deck height	This is an Improved ZLI Block Good for 650 H. P.