- series ▁engines ▁in ▁the ▁M X 6 ▁were ▁based ▁on ▁the ▁same ▁engine ▁block ▁and ▁included ▁those ▁found ▁in ▁the ▁Ford ▁Pro be , ▁X ed os ▁ 6 , ▁and ▁M X - 3 ▁V 6 ▁models . ▁The ▁K L ZE ▁had ▁about ▁ 4 0 ▁more ▁horse power ▁than ▁the ▁K L DE ▁versions ▁for ▁a ▁few ▁reasons . ▁Although ▁the ▁disp lacement ▁was ▁the ▁same , ▁the ▁K L ZE ▁had ▁more ▁dur ations ▁on ▁the ▁c ams , ▁higher ▁compression ▁due ▁to ▁a ▁different ▁shape ▁of ▁p ist ons , ▁and ▁the ▁int ake ▁manifold ▁was ▁different ▁on ▁the ▁Z E . ▁The ▁K L - ZE ▁int ake ▁manifold ▁run ners ▁were ▁shorter ▁and ▁wider ▁than ▁the ▁K L - DE ▁manifold . ▁Also , ▁the ▁heads ▁on ▁the ▁K L - ZE ▁were ▁port ed ▁and ▁sh aped ▁differently . ▁Not ▁only ▁was ▁the ▁Z E ▁higher ▁in ▁compression , ▁but ▁it ▁was ▁also ▁a ▁higher - rev ving ▁engine . ▁The ▁only ▁fla ws ▁in ▁the ▁K L - ZE ▁design ▁were ▁the ▁we aker ▁val ve ▁spr ings ▁on ▁the ▁int ake ▁val ves . ▁This ▁is ▁usually ▁corrected ▁by ▁using ▁the ▁K L - DE ▁spr ings , ▁keep ers , ▁and ▁retain ers ▁which ▁are ▁stronger . ▁ ▁Four - w heel ▁ste ering ▁was ▁used ▁from ▁ 1 9 8 7 ▁to ▁ 1 9 9 8 ▁on ▁both ▁M X - 6 ▁GT ▁and ▁G E ▁models . ▁Four