Stock oil pressure sensor W/ aftermarket guage

[SDLiberty]

Ok so i've looked around in the HOW-To sec. and seems as though no one has come up with a solution for adding a oil pressure gauge while still being able to use the stock sending unit. (or i just didn't find it?) My question is... Will this work? I don't know the thread spec for our oil filters. Are they a 3/4-16 thread?
http://www.egauges.com/vdo_indA.asp?PN=CON-021
Or would one of these be a better solution?
http://www.egauges.com/vdo_indA.asp?PN=240-855

 

[Marlon_JB2]

From what I've read over the years, its better to have a T-Adapter.