1969. It was the product of placing the stroke crankshaft into a bore cylinder-block. The 1967 302 used the same crankshaft stroke as the 283, with a forged steel crank that was also produced. This block is one of three displacements, 302/327/350, that underwent a crankshaft bearing diameter transformation for 1968 when the rod-journal size was increased from the diameter small-journal to a large-journal and a main-journal size that was increased from to . DZ 302. The large-journal connecting rods were thicker (heavier) and used diameter cap-bolts to replace the small-journal's 11/32. 1968 blocks were made in 2-bolt and 4-bolt versions with the 4-bolt center-three main caps each fastened by two additional bolts which were supported by the addition of thicker crankcase main-web bulkheads. When the journal size increased to the standard large-journal size, the crankshaft for the 302 was specially built of tufftride-hardened forged 1053-steel and fitted with a high-rpm diameter harmonic balancer. It had a 3/4-length semi-circular windage tray, heat-treated, magnafluxed, shot-peened forged 1038-steel 'pink' connecting rods, floating-pin in '69, forged-aluminum pistons with higher scuff-resistance and better sealing single-moly rings. Its solid-lifter cam, known as the "30-30 Duntov" cam named after its /0.030 in hot intake/exhaust valve-lash and Zora Arkus-Duntov (the first Duntov cam was the / 1957 grind known as the '097, which referred to the last three digits of the casting number) the "Father of the Corvette", was also used in the 1964-1965 carbureted 327/365 and fuel injected 327/375 engines. It used the '202' / valve diameter high-performance 327 double-hump '186 and 461 heads, pushrod guide plates, hardened 'blue-stripe' pushrods, edge-orifice lifters to keep more valvetrain oil in the crankcase for high-rpm lubrication, and stiffer valvesprings. In 1967, a new design high-rise cast-aluminum dual-plane intake manifold with larger smoother turn runners was introduced for the Z/28 that the /370 hp 1970 LT-1 also used. 1969 Corvette and 1970 Z/28 engines were equipped with a Holley carburetor until the Q-jet carburetor returned in 1973. Unlike the Corvette, the exhaust manifolds were the more restrictive rear outlet 'log' design to clear the Camaro chassis's front cross-member. It had a chrome oil filler tube in the front of the intake manifold next to the thermostat housing from 1967 to 1968. The first year had unique chrome valve covers with Chevrolet stamped into them without an engine displacement decal pad. In 1968, the engine had the chrome covers, but without