You can order everything from Radium. Actually, if you wanted to run open, you could as they sell a grommet and filter that attaches as well. This is the competition catch can, short version. They also make a standard one that is slightly smaller but just as nice that is about 1/2 the price. You spec the inlet and outlet fittings that you want. It took some research to figure out the optimal fitting sizes and arrangement, but I have it down if you have a Gen 4 car including the size of heater hose for attachment. I ended up putting blue earls fittings on mine because I spec'd the wrong size on one of the fittings I ordered from Radium so I just drove to the Earls Distribution center here in Indy and bought new ones....they didn't have black for one specific fitting and I didn't want to mix and match colors. Not to mention, the blue matches the car.
If you decide to go with one that uses the same 7/8"-14 threads in the can, I have a couple extra 90deg swivels available for cheap that I won't use since they cost like $30-40 each!
For Gen 4, you need -10AN barbed hose fitting inlet and outlet, 5/8" ID heater hose, and a couple zip ties to move the heater and overflow hoses out of the way. You could use smaller -AN fittings like -8 or -6 but then you would need reducers and adding additional connections that increase the chance of leaks. You'll need a tap and die set and a good drill/bit to drill 2 holes in the frame support. I ended up using 1/4" x 20 TPI allen head bolts and lock washers on the bracket. I threaded the holes rather than drilling all the way through the crossmember. My plumbing was a bit more complex just because I needed the hardline running to the Gen 5 intake but with a Gen 4, you could just run heater hose on both sides and be set as the attachment on the Gen 4 intake is 5/8".
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