I have a single line oil system on a big block.with a M63HV pump.and a Muscle Motors filter addaptor. I added a remote dual oil filter set up. will it afect the oil pressure? Thanks!

No it wont, it'll require a little more oil to fill
it thats all

If you use a Mopar- Ford type oil filter adapter it will have no affect on the oil pressure down low in the rpm range, it may have negative effect above 5500 rpm I had two dual oil filter mounts that did make the pressure drop above 5500 rpm. If you use a dual oil filter adapter that uses the GM filter it may affect the oil pressure as they are full flow filters with no internal bypass built in like the Ford/Mopar oil filters have