I think its possible to T off the original and maintain your stock oil pressure gauge too without affecting accuracy. The stock one is right in front of the first cylinder on the driver side. It should have a factory extension of some sort on it already.
Kevin
Yep, fab a Tee. the factory thread is 1/4" NPT. most aftermarket senders are 1/8" NPT. the local hardware store should have everything you need. good time to get a new stock gauge sender (10 bucks at parts stores).