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Old 06-23-2010, 01:28 PM
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RippinRon RippinRon is offline
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The m20, m21, etc are rpos I think had more to do with being close and wide ratios. My old boss had a 79 camaro with a factory 4 speed it was a super t10 and had the m21 rpo on the option sticker. Muncies supposedly didn't come in vehicles past 74 or 75 but some Canadian cars received them later on. I guess they were using up old stock.
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