I was just reading a few good threads about that T last night, There are T's you can buy that fit into the block and oil pressure sending unit with no mods, its like 20$. But if you get the T npt an tap the hole, it will work fine, the oil pressure sending unit is NPT anyways (now why would they do that?), this is the route Im going, I bet the T is 5 bucks at osh. Now if I could remember what size... time to find the threads I was reading last night!
On a side note: I just finished my rear suspension so now I have KYB all around, I wasnt used to it and a hit a speed bump to fast, ouch. Oh, and I did my rear suspension without taking the axle off like I was told I would half to.