Quote:
Originally Posted by stsalvage
Most of you young people where not around when this happened.Over 1000 to 5000 blocks came out of Canada they they had a bad casting.They would not clean up to standard bore 396.Instead of GM scraping the batch they Bord them to 30 over turning them in to 402's
I be leave this happened in 1969.From 1970 you can kinda see that GM wanted to get rid of these motors....
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I don't think this is true for many reasons. Here is a much more plausible explanation:
"The 402 was phased in starting in either late December 1969 or January 1970.
The 396 was bored .030 over to 402 to meet emmission standards. The slight increase in size allowed Chevrolet to use the larger motor emmission standards and allowed them to keep the same HP and torque ratings. Starting with cars manufactured in January 1970, higher emission standards were in effect. To address these new standards additional strain was placed on the motor (either via smog pump, lower compression, other emissions equipment or various combinations) so the few extra cubes were needed to make up for the additional power drain.
Since they had invested so much in the SS396 name and mystique, they simply kept the name and gave customers 6 extra cubes for their $$$$. I don't think they would have hurt anything by renaming it SS402, but that's just my opinion..."
https://www.chevelles.com/forums/19-...-vs-402-a.html