Edelbrock Cylinder Head E-Street Big Block Chrysler Complete Pair

Intended for installation on 1965-1976 Small-Block Oldsmobile 350-403 c.i. engines equipped with a hydraulic roller camshaft, these 356-T6 aluminum casting cylinder heads (#61035) are a modern refinement to our #6051 heads, except they can accommodate a factory-style mechanical fuel pump. A smaller 68 cc combustion chamber achieves a more appropriate small block compression ratio compared to our PN 61025/61029’s larger 77 cc chamber, which yields a lower compression ratio than most engine builders desire on a small block engine. These heads require a 3.9375” minimum bore and feature a modern chamber design with optimized spark plug positioning. Maximum airflow is achieved through the factory 6-degree valve angle using high-flow 200 cc intake and 130 cc exhaust port volumes, along with 2.072” intake and 1.680” exhaust valve sizes in their O.E. positions. A finished deck thickness with added material above the intake port and pre-counterbored head-bolt holes for .5” diameter studs provide extra clamping force in key areas. A stud-and-guide plate valvetrain system (as opposed to the O.E. pedestal type) provides a solid foundation for the beefier diameter pushrods, and Helicoil inserts in the exhaust and rocker stud holes keep bolts secured. However, there are no provisions for a heat crossover.
Although these heads will fit on Big-Block Oldsmobile engines, the 68-cc combustion chamber size is not ideal for a big-block application as it will raise compression. See PN61025 and PN61029 for big-block specific cylinder heads.
For 350-403 c.i. Olds engines with a hydraulic roller cam, these heads are made of 356-T6 aluminum and feature 68 cc chambers, high-flow 200 cc intake and 130 cc exhaust port volumes, and 2.072” intake and 1.680” exhaust valve sizes.
356-T6 Aluminum Casting, 68cc Combustion Chamber Volume, 200cc Intake Port Volume, 130cc Exhaust Port Volume, 2.072” intake and 1.680” exhaust valve sizes, 3/8” dia. Pushrod diameter, 5/8” Finished Deck Thickness

• Retains compatibility with OEM and popular aftermarket manifolds and Headers
• Maximum compatibility with OEM and aftermarket components
• Allows the use of an “OEM” style mechanical fuel pump
• Mechanical Fuel Pump Clearance Cutout
• Factory 6-degree valve angle
• OEM Port Locations

Edelbrock introduces its new E-Street 15-degree LS3 69cc cylinder heads (PN 77620) as a premium replacement option, ensuring great power on any high-performance or stock GM LS3 engine build. These heads offer the best performance value of any aftermarket GM LS3 head.

Sold in pairs and assembled with premium COMP Cams® valve train components, these LS3 heads are engineered with the same architecture as the factory head, and all stock components will fit without issue. The assembled heads feature Beehive™ Valve Springs, chromoly steel retainers, heavy-duty stainless-steel & Inconel valves, and top-quality valve seals – all inspected and assembled by qualified Edelbrock technicians. The intake valve size is 2.165” while the exhaust is 1.590”. The Beehive Valve Springs allow up to .570” lift camshafts, ideal for many mild to hot camshaft grinds.

Edelbrock E-Street 15-degree LS3 cylinder heads are manufactured with premium aluminum alloy, machined to the industry’s tightest tolerances. They feature manganese bronze valve guides for extended wear, with particular emphasis placed on holding precision tolerances on valve seat concentricity. This allows the valves to seal securely, eliminating any leak-down and increasing cylinder pressures during engine operation.

All Edelbrock cylinder heads feature patented Clean Cast Technology™, a revolutionary process that eliminates casting flaws and promotes a smoother internal surface finish for greater air and coolant flow. These benefits provide more power and increased cooling ability right out of the box. A unique dual spark-plug-pocket design allows you to use the factory-style tapered-seat spark plugs or gasket-seat spark plugs available in wider heat ranges for maximum tunability.
The E-Street Cylinder Heads for GM LS3 are designed as premium quality, bolt-on-ready cylinder heads for any high-performance or stock replacement application. The chambers are 69cc, while the Beehive springs allow .570” lift camshafts.

• 2.165″ Stainless Intake Valve, 1.59″ Stainless Exhaust Valve
• Sold in Pairs (2 complete, assembled heads per part number)
• Ready to bolt on out of the box
• GM LS3 Compatible