The LM1 moderate-compression 4-barrel carburetor 350ci engine was introduced at the beginning of the 1969 model year as the replacement for the L30 327/275HP engine. The LM1 was, in turn, replaced mid-way through the model year by the lower-performing L65 2-barrel carburetor 350ci engine, and most of the higher performance features of the LM1-equipped vehicles were not transferred to the L65 units. Even more so than with the L30/M20 in 1968, it was possible with the LM1 to create a SS-350 look-alike in most performance features. The absence of SS badges and SS hood/hinges, both easily added, are the only easily distinguishable clues between a L48-powered SS-350 and a LM1 with added J52 disc brakes, N10 dual exhaust, D90 stripe, one of the 70-series tire options, and the Z87 custom interior (which provides hood insulation). Closer examination of the original engine is required to note the lower compression heads, the distributor code, and/or the engine application code. The 7-inch SS wheels were also not available on the LM1/M20.
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