need help installing mechanical oil pressure gauge

Ok i did look this up before i posted this but i didnt understand so i will ask for a little more detail. Last night this guy told me that you plug it into this round thing next to the oil pan. I just went to look at this and im not seeing that happening so Some pic would be great. thanks

Its not that easy you have to hook it up to the oil pressure sending unit.

uh...kinda off topic, but bro, you may not want to install the mechanical ones. I was in a similar situation, and they guys at the shop told me that cheap mechanical oil pressure guages can cause the unit to fail...since the way the gauge works is by physically having a tube that sends in oil to the gauge itself, a dysfuntional gauge could mean very, very hot oil sprayed on your face while driving. I highly recommend getting an electronic one.

unscrew the oil sending unit that the arrow points to in the pic.this is for the gauge in the cluster.after you get it out use a 1/8 pipe thread tap and run it in about a 1/4 of an inch or till it bottoms out.the tap will stop do not force it no more.then the fitting will screw in and use teflon tape or so on.i would put up a pic of mine but my batteries are dead in the digi.this is how i did mine and this pic i found for you to see.
OR USE THE ELECTRICAL ONE IF YOU WANT,YOUR FACTORY GAUGE WILL NOT WORK IF YOU DONT USE THE SENDING UNIT INLINE WITH THE MECHANICAL GAUGE ONE.I JUST USED MY MECHANICAL GAUGE ONLY NO SENDING UNIT INLINE.
http://img.photobucket.com/albums/v642/courtlyn/landry.jpg

Well the factory gauge is worthless anyways so i could just tap it into an oil line. When i got the gauge last time it only had a hose and the same stuff that came with the boost gauge. So will i have to go buy another (t) fitting for the hose to plug into.
you get it out use a 1/8 pipe thread tap and run it in about a 1/4 of an inch or till it bottoms out.the tap will stop do not force

This is the hose that it comes with but if I plug this into that space than it wouldnt screw back on into the space

Pipe taps should never be run all the way in, only far enough so that the fitting goes in enough that it gets tight before its out of thread. This goes for all tapered threads (NPT, BSP, etc). Just wanted to elaborate there a bit for poeple that may be unfamiliar with how tapered pipe threads work. Its like cutting, you can take mroe off, but you can't put it back on.

The port is already 1/8th inch, but its BSP (british standard pipe). Gauges parts are typically NPT (National Pipe Thread). Autometer sells the BSP to NPT adapter, and www.mcmaster.com will have them too. The difference is 1 thread per inch. So tapping will work, but you will have less than ideal thread to thread contact area.

The hosuing in the pic is also obviously a 90 housing. The 2g housing (and probably 91-94 as well) will have two stock oil pressure senders on it. The one on the front (radiator) side is for the idiot light, which I would keep, and the rear (firewall) side sender is for the stock guage, which is useless. So I would replace the rear.

I will also advise against the mechanical guage. I have had them leak before, and it makes a mess ;) Even if you plumbing is balls on, the guage itself can fail, the tubing can fail, etc. Too risky. The autometer guage I use is only 48 bucks or so, quite inexpensive.

I went to the the auto store today and i found that auto meter makes a brass hose similar to the plastic one that you get in the box. I was wondering if this would make a big difference in the possibilites of the guage leaking. If so than i might as well go with the one im getting.