SD-4 BLOCKS
10093306-Cast Iron Super Duty Block
Pontiac Motorsports' four cylinderSuper Duty block is cast specially formulated grey iron with a tensile strength of over 47,000 psi. This premium material strengthens the casting and improves ring seal. The Super Duty block has rough-bored 3.750" diameter cylinders; the walls are siamesed to optimize coolant flow around the bores. The cylinder barrels are lengthened to accomodate long-stroke crankshafts. The two-bolt main bearing caps are installed with 1/2-13NC Grade eight bolts; the reinforced head bolt bosses are also tapped for 1/2" fasteners. This block has provisions for left or right-hand starter motors.:
TECHNICAL NOTE: This block uses five needle roller camshaft bearings. Bearings and camshafts are availible from aftermarket manufacturers.: