Quote Originally Posted by PJG1173 View Post
couldn't you T into one of the oil cooler lines or the oil pressure sender? I also know on some small blocks there were oil senders in the block just above the oil filter along with the one behind the intake.
You could in theory "T" in an oil cooler line if so equipped .

The port on a SBC above the filter is tapped 1/4" NPT , the one behind the distributor is 1/8" NPT . BBC uses a 3/8" NPT above the filter and 1/4" NPT along the pan rails .

IMHO , all fluid temps (Oil , Trans, etc) should be measured in the sump , as that is the fluid that the engine (or trans , etc) will be using.

TOM