I HAVE A 280GE GWAGON WHICH HAS BEEN CONVERTED TO A DIESEL I NEED A MANIFOLD TO FIT THE DIESEL WHICH HAS AT THE MOMENT A SMALL BORE DOWNPIPE THE ENGINE IS A 617 SERIES BUT THE NEW DOWNPIPE I HAVE HAS A MUCH LARGER BORE THIS I KNOW SHOULD BE RIGHT AS IT IS A GENIUNE MERC PART FOR A 3000DIESEL G WAGON ANY HELP PLS