HI DOUGAL I THINK HE WAS REFERING TO THE POST JUST BEFORE MY LAST ONE OF THE DSL WITH THE SHEET METAL VLV CVR , THAT IS THE ONE THAT LOOKS LIKE THE OLDER MODEL 4BD1 NOT THE ONE WITH THE ALUMINUM VLV CVR , I NEVER SAW A 4BD1 WITH T HE ALUMINUM CVR , WHAT WE GOT HERE IN THE STATES ON THE 4BD1 ENG EVEN THE OLD ONES IN THE KS22 TRUCKS HAD TWO CVRS ONE ON TOP OF THE OTHER WITH AN INSULATING PAD BETWEEN THEM TO TRY AND QUITEN THEM DOWN SOME .. JERRY