I noticed in this month's Hemmings Muscle Cars in the feature article on the '67 SS427 Impala that the author listed one of the engine options as the 427/425. While there's no doubt that this engine WAS available in '66, '68, & '69 I have always been under the impression that in '67 the 425 horse option was not offered for some reason. In a visit to Floyd Garrett's Muscle Car Museum in Sevierville, Tenn last year, he shared the same opinion. Why ONLY the smaller horsepower 427 was offered in that year when the 425 was available in prior and subsequent years seems to be a mystery that no one seems to know the answer to. Comments?????

Check here.May help answer your question about the L-72. Jim
http://www.impalass427.com/