If you're converting from a 90 degree adapter to the std one? mopar part number 2206372 it is the same bolt w-w/o the 90 degree adapter. So you could, if converting, use the one from the 90 degree adapter oil filer mounting. Or call chrysler and see if you can just buy a new one.
[ame="http://www.ebay.com/itm/Mopar-OIL-FILTER-MOUNTING-PLATE-Adapter-318-340-360-Dart-Cuda-Duster-LA-eng-/321438482448?pt=Vintage_Car_Truck_Parts_Accessories&hash=item4ad73a0010"]â Mopar Oil Filter Mounting Plate Adapter 318 340 360 Dart Cuda Duster La Eng | eBay[/ame]
$46.69 here for the whole kit with a buy it now.