1971 340 oil filter adapter plate question
 

My son and I are working on a 340 engine. We have had to take off the 90 degree oil filter adapter and put on a straight adapter because of clearance issues with some Hooker headers we are installing. We got the straight adapter plate from a 318 we have. The 318 has a plug in a threaded hole in the block to the left of where the adapter screws on. The 340 also has this threaded hole but it is open with no plug in it. Is this something we have to block off now because of the different filter adapter?