thickened for use with the plastic timing cover (redesigned for use with a crankshaft position sensor with integrated dowel pins - cylinder blocks for 1996+ do not have dowel pins in the timing cover flange) held with 8 bolts and the water pump bypass hole on the RH deck and below the water pump passage undrilled. Also the fuel pump boss is still present but undrilled (which dates back to the 1992 model year for production engines without a fuel pump blockoff plate - some marine/industrial blocks and crate motors sold over the counter via GM dealerships e.g. Goodwrench, ZZ6, 350 H.O. retain the use of a mechanical fuel pump). This was the last change for the Generation I engine, which continued through the end of the production run in 2003; all 1997–2003 Generation I engines were "Vortec" truck engines. Details Chevrolet Generation I V8 Small Block Engine Table note 1: depending upon vehicle application; horsepower, torque, and fuel requirements will vary. Generation II GM small-block (1992–1997) General Motors' Generation II LT1 is a small block V8 engine. Making its debut in the 1992 Chevrolet Corvette, the new LT1 sought to draw upon the heritage of the 1970 Chevrolet LT-1. A significant improvement over the original Generation I V8 is the Generation II LT1's "reverse cooling" system, allowing coolant to start at the heads and flow down through the block. This keeps the heads cooler, affording greater power through a higher compression ratio and greater spark advance at the same time it maintains higher and more consistent cylinder temperatures. Some parts from the Generation II are interchangeable with the Generation I one-piece rear main seal engine. The interchangeable parts include the rotating assembly (crank shaft, pistons, connecting rods, and flywheel/flexplate) one piece rear main seal housing, oil pan and valve cover gaskets and valvetrain assembly (not including timing set, which includes a gear to drive the water pump). The LT1 uses a new engine block, cylinder head, timing cover, water pump, intake manifold and accessory brackets. The harmonic damper also does not interchange; it is a unique damper/pulley assembly. Engine mounts and bell housing bolt pattern remain the same, permitting a newer engine to be readily swapped into an older vehicle. 4.00 in bore blocks 5.7 L LT1 In 1991, GM created a new-generation small-block engine called the "LT1 350", distinct from the high-output Generation I LT-1 of the 1970s.