Cylinder Head, Aluminum, Oval Port, Assembled, BB Chevy
This GM Performance Parts Oval Port Cylinder Head will fit all 1965-1996 Mark IV and Gen V or VI 396 thorough 502 cubic inch big block Chevrolet engines. It has been fully machined with semi-finished Bronze Alloy guides and semi-finished valve seats that use 2.19/1.88" valves. It comes with 2.19 stainless steel intake valves, and 1.88 stainless steel exhaust valves with 11/32 stems. Also included are high performance valve springs, valve spring caps, keys and valve stem seals. These high velocity 290cc intake runners enhance mid range throttle response and torque. The exhaust runner volume is 110cc., the 110cc semi open combustion chamber design will make a very streetable compression ratio. Spring DIA is 1.55", with 7/16" rocker stud holes. These accept all stock accessory brackets except Gen V where the bracket holes have been enlared to 7/16". The roller studs and exhaust bolt holes are heli-coiled for strength.
Technical Notes: These heads are made from 356-T6 aluminum alloy. The 9/16" deck surface is for maximum strength and greater head gasket sealing. Designed for 3/8" push rod diameter. These heads require cylinder head bolt kit P/N 12367779. Use the following performance head gasket:
For 502ci engines, use head gasket kit P/N 12363411 and no sealant on the head bolt. 1965-90 with standard bore to 4.370" use P/N 12363414 and with 4.47" to 4.540" use P/N 12363413, and with GEN V 1991-98 engines with standard to 4.370" use P/N 12363412, with bores of 4.47" to 4.54" use gasket P/N 12363411. The semi-finished bronze guide can be finished either 11 /32" or 3 /8" . The interlocking hardened valve seat will accept leaded or unleaded gas. Use intake gasket P/N 12366985, with intake bolt kit P/N 12367959.
Use the following components for service:
P/N 12366986 Intake Valve 2/19"
P/N 12366988 Exhaust Valve 1.88"
P/N 12462970 Valve Spring
P/N 12366990 Valve Spring Retainer
P/N 3875916 Valve Spring Shim (Requires 2)
P/N 12366992 Valve Lock
P/N 12366993 Oil Seal