Chevy Big Block
Big Chief Big Duke 18°- Dome Top

• Designed for large nitrous kits. 2618 alloy.
• Top gas ports for maximum ring seal.
• Ratios figured for .010” to .020” deck@9.800” and 10.200”.
• Back-cut .043” (.175”) x 1/16” x 3/16” ring package.
• Premium H-13 wrist pins included.
• Gasket Volume - 11.3cc.
• Top ring down = .340”@1.240”cd to 1.270”, .290”@1.120”cd.
• Designed for 2.400” diameter intake an 1.950” exhaust valves.
• Valve relief depth = .315” and .068” exhaust.
• Some items are non-stock parts, made to order as necessary. See the shopping cart for availability.

Big Block Chevy : 9.800" Deck Height Ratios figured from 0.10" to 0.12" deck @ 9.800
Part #	Bore	Stroke	Rod	C. D.	Wt	Pin	CC's	Comp Ratio			Purchase Online
								82cc	87cc	97cc
								13.8 13.9 14.1 14.3 14.4	13.1 13.2 13.4 13.6 13.7	12.0 12.0 12.2 12.4 12.6
12750* $911	4.500 4.530 4.560 4.600 4.625	4.250	6.385	1.270	638 643 650 669 -	.990	13.0				Discounted Prices
12758* $911	4.500 4.530 4.560 4.600 4.625	4.250	6.535	1.120	- 595 600 613 -	.990	13.0	13.8 13.9 14.2 14.5 14.6`	13.0 13.2 13.5 13.8 13.9	11.9 12.0 12.3 12.6 12.7	Discounted Prices