The Tial wastgate comes with 2 brass fittings, one in the lower part and one on top. Which one are you suppose to use or do you use both?

If you are using the wastegate to regulate boost use the bottom, if you are using a manual boost controller use the bottom, if you are using an electronic like the Profec B, you will need both.
John

Thanks alot, but what is the top one for?

A wastegate has a diaphram in it *** a spring, the spring is rated for a certain pressure, when greater than that opressure is applied to the bottom of the diaphram/spring, the wastegate opens. An electronics boost controller applies pressure to the top to *trick* the actuator into thinking that there is less pressure than there really is, make sense?
John

Makes sense, thanks again. If u read this maybe u can answer this question. The turbo compressor housing has also a brass fitting, I was told this connects to the wastegate with a vacuum hose to regulate the boost, is this true. Oh, turbonectics t3/4 ball bearing.

It can be done, however I usually plug it and use one off of the intake manifold, that way boost is regulated after the pressure drop of the intercooler.
John