For 2014, they’ve developed new Fast Burn cylinder head castings that incorporate beehive-style valve springs and complementing valvetrain components.The result is greater high-rpm range and durability – and power.The heads are the stars of an all-new ZZ5 350 crate engine and an updated version of the big-torque ZZ383 stroker engine. These ZZ5 engines are not intended for marine use and should only be used in 1979 and earlier pre-emissions street vehicles or any year of off-road vehicles. Parts used in these engine assemblies are 4-bolt main 1-piece rear main seal blocks forged steel crankshafts powdered metal connecting rods and flat-top hypereutectic pistons.
Nov 22, 2015 · For the record, I wasn't suggesting that anyone go buy a crate engine. You can duplicate the ZZ5 performance for cheap using a late model roller block. An engine like the ZZ5 will destroy a 11:1 CR stock DZ 302 in a street '69 Camaro Z/28 with a Muncie and street friendly 3.31-3.73 gears.