Mechanical gauges on a LS swap

[softballnrd27]

Here is my swap:
85 SWB, 2004 6.0l w/Vic Jr 4150 style TB and some other goodies backed by a th400

My questions are:
Can you use mechanical gauges for the oil press, and water temp? If so, where can I get the appropriate adapters that go into the block/head?

I will be swapping out my dash for a 64-66 truck dash and I don't want to buy good gauges until then. I already have the mechanical water and oil pres and would like to just hook them up. I will still be able to use my speedo with the pass thru VSS from Dakota Digital and i am buying my tach bc I am going to mount it on my dash.