I looked through some archives that JaySS linked to a while ago. According to the archives and what I can see, it looks like the only easily accessible threaded port for an oil pressure sender would be at the LT1 oil filter/cooler adapter. I figured I'd ask in case there's some other usable location. Getting to the backside of the block where the oil pressure switch is isn't very easy and I'd rather just leave that setup alone.