They are different. Get a setup from a 91 or later Magnum block.
This is from a rebuild engine book I have and this info is correct.
1991
This was the year that Chrysler standardized all of its oil filters, so it made some very subtle changes to the block, along with a few other related parts:
•The threaded boss that the oil filter adapter screws into was shortened by about .250". It was now even with the machined surface on the inside diameter of the filter casting instead of being flush with the cast surface on the block.
•The threaded oil filter adapter was about 0.250" longer. It measured 1.460" in overall length instead of 1.240"
•The arch of the adapter plate was changed to match the shorter length of the boss. The new plate (p/n 53009219) can be easily identified because it has six holes instead of the four that were used on the earlier plate.
