s ▁V 8 ▁was ▁changed ▁to ▁one ▁with ▁overhead ▁val ves . ▁Ch rys ler ▁replaced ▁its ▁straight - e ight ▁with ▁its ▁famous ▁H emi ▁V - 8 ▁for ▁ 1 9 5 1 . ▁Hudson ▁retired ▁its ▁straight - e ight ▁at ▁the ▁end ▁of ▁the ▁ 1 9 5 2 ▁model ▁year . ▁Bu ick ▁introduced ▁a ▁( 4 . 0 " ▁bore ▁× ▁ 3 ▁" ▁stroke ▁= ▁ 3 2 2 ▁in ³ ▁( 5 . 2 7 7   L )) ▁V 8 ▁in ▁ 1 9 5 3 , ▁with ▁similar ▁disp lacement ▁as ▁their ▁( 3 ▁" ▁bore ▁× ▁ 4 ▁" ▁stroke ▁= ▁ 3 2 0 . 2 ▁in ³ ▁( 5 . 2 4 7   L )) ▁straight - 8 , ▁the ▁latter ▁being ▁produced ▁until ▁the ▁end ▁of ▁the ▁ 1 9 5 3 ▁model ▁year . ▁Pont iac ▁maintained ▁production ▁on ▁their ▁straight - e ight , ▁as ▁well ▁as ▁a ▁L - head ▁inline ▁six , ▁through ▁the ▁end ▁of ▁the ▁ 1 9 5 4 ▁model ▁year , ▁after ▁which ▁a ▁V 8 ▁became ▁standard . ▁Pack ard ▁ended ▁production ▁of ▁their ▁signature ▁straight - e ight ▁at ▁the ▁end ▁of ▁ 1 9 5 4 , ▁replacing ▁it ▁with ▁an ▁overhead ▁val ve ▁V 8 . ▁ ▁By ▁the ▁end ▁of ▁the ▁ 1 9 7 0 s ▁overhead ▁val ve ▁V 8 s ▁power ed ▁ 8 0 % ▁of ▁autom ob iles ▁built ▁in