Installation of the collectors is very simple. The collector pipes
connect to the headers and then meet together at the bottom of the turbine housing.
These pipes spool the turbo as the exhaust flows through the housing on its way out
of the downpipe. See the photo to the right for connection.
The collectors need to be installed from the bottom of the car. In order to get them up into position, the modified cross member must be removed. It helps to have a helping hand there to hold the top of the collectors while you attach the pipes to the headers.
These header/collector flanges use a
2-1/2" gasket with 3" bolt pattern. I suggest using metal collector
gaskets right from the start as I blew out the paper gaskets I originally used within 2
days.
In the photo to the left, you can see how the collector pipes run under the car.
The pipe from the front header comes down and goes straight across the front and
then up to meet the turbo. The pipe from the rear header comes down and then forward
where the y-pipe would normally run from the front header backward. 
It then meets the pipe from the front and turns across and then up to the
meet the turbo.
From the top, you can see the rectangular flange that the turbo sits on. There is a metal gasket between the turbo and the collectors. The turbo is then held down by four studs.