The story
GM's sheets list the L48 350 and the big-blocks with the SS (marked Z27 in 1971–72); the big-block was the L34 or L78 in 1970 and the LS3 in 1971–72. GM's 1970 sheets also list an SS 454 (LS6), which Wikipedia says never reached production.1234
1972 was the last year of the SS 350 and SS 396, by Wikipedia's account.4one source

















