The oil blockoff plate is just a piece of machined aluminum with NPT ports on it. You can get it with two or four ports and with different threads. The oil pressure sender I'm talking about is a resistance sender with one wire to hook up. Here is a link to the gauges I have on order:
http://newvintageusallc.mybigcommerce.com/73201-05/
I don't see many guys using New Vintage for some reason. I like them because they're reasonably priced and they have some cool designs. They're different from Dakota Digital in that there isn't one or two plugs going to the gauge cluster, rather one plug for the tach, one for the speedo, and then individual wires to the fuel/oil/water/volts. This cluster comes with the oil pressure sender and water temp sender, both of which are 1/8-27 threads. This may be more info than you want, but it's what I've learned from doing my dad's New Vintage gauges and what I'm going to do on mine:
-Don't put any kind of thread sealant on the temp sender bushing or sender threads as it will increase resistance and make the gauge read high.
-You may have to install a resistor inline on the temp sender wire depending on what your gauge reads. I would connect it and test it out without one but be prepared to install one.
-In order to use any of the warning indicators, you have to use a relay. I am using one of the indicators as a low brake pressure warning light and another as a check engine light. Since both of these are ground triggers (one from the prop valve and the other from the PCM), you have to send those ground triggers through a relay to send a 12V signal to the indicators and turn them on.
-Oil pressure hookup is easy-just one wire to the sender.
-Tach more or may not need a resistor (powered), depending on what engine you have. More info on this from LT1Swap and in the New Vintage instructions.