standards. Chevrolet vehicles eventually used the as their base V8 engine. The 267 when introduced in the GM F-Body as the L39 4.4 L it made at 3600 RPM and of torque at 2000 RPM (SAE NET). Power output would drop in subsequent years of the engine. The had a low 8.3:1 compression ratio. Major changes The original design of the small block remained remarkably unchanged for its production run, which began in 1954 and ended, in passenger vehicles, in 2003. The engine is still being built today for many aftermarket applications, both to replace worn-out older engines and also by many builders as high-performance applications. The principal changes to it over the years include: 1956 – Full-flow oil filtration was introduced, using a paper element filter in a canister that was mounted to a boss that was added to the left rear cylinder block casting and machined for this purpose. 1957 – The displacement of the base V8 continued at 265 cubic inches, but optional V8 engines were introduced with a displacement of 283 cubic inches. 1958 – Bosses for side motor mounts were added to the block casting, used for production mounts for this and all future model years. However, the features for front motor mounts as used in 1955–1957 remained part of the block casting in this and future years. The 265-cubic-inch version of the engine was discontinued. Also, the cylinder head valve cover mounting bolt holes were changed from the top row staggered (relative to the bottom row of bolts) to the "straight-across" pattern that remained the way of identifying the early heads from the newer ones with a valve cover design which lasted until the 1987 center-bolt-style covers. 1962 – The block's cylinder wall casting was revised to allow four-inch bores, and the 327-cubic-inch version of the engine, using this bore diameter and increased stroke, was introduced. 1967 - The oil filter mounting now came from the factory with an adapter and machining to allow the use of spin-on filters; canister mounting was possible by removing the adapter. 1968 – The main-journal diameter was increased from 2.30" (small) to 2.45" (medium), and the connecting-rod journal diameter was increased from 2.00" to 2.10". This allowed the use of cast-iron crankshafts; the previous crankshafts were made of forged steel, which was more expensive. The rod bolts were changed from 11/32" diameter to 3/8". The oil-fill location was