To hook up a mechanical oil guage you need to install a fitting in your block and feed oil via a line (nylon tubing or braided) throught the firewall to your guage. Pretty easy to do since most good oil guages come with the hardware required.
To hook up an electrical oil guage, you need to get a sensor (sending unit) and fit that into the block. Then you run electrical wires from the sensor through your firewall up to the guage. It's up to you, which way you want to go.
I use an Autometer 4721 mechanical guage on my 454 big block. However, I don't trust nylon tubing, so I ran a -3 braided line to my guage. It's pretty easy to do -- just get an NPT to -3AN fitting to fit into the block and hook up a -3AN braided line from that fitting to your guage (you'll need another -3AN to NPT fitting on the guage). More expensive than running nylon tubing but more reliable in the long run (you definitely don't want oil spraying under your dash if the nylon tube should ever brake! :? )
The Autometer 4727 is an electrical guage an comes with the sensor and NPT fittings for your block. (Note -- I'm using Autometer guages as examples because I was looking at carbon fibre guages to match my interior, but there are tons of other models available).
Best place to mount your take-off fitting (or sensor) is on the driver's side towards the front of the engine, right below the head. You could find a take-off point on the rear of the block, but if you loose oil pressure, the front take-off point will give you an earlier warning.
Hope this helps.
Andry
