The predecessor to it - the 225 c.i. 90 degree V-6. It was sold to AMC in that size, and used in Jeeps in the early 1970's. Then Buick bought back the tooling for it in 1974, enlarged it to 231 c.i., and put in in the Skyhawk subcompact first in 1975, and then the rest of the line in 1976....