post a photo of your engine bay, so we can see your custom piping.
If you are still running the stock crossover piping and its just your intake and hot pipe thats changed, you will just need to get a bung welded onto the intake pipe, a stock bov and a return pipe.
I have a stock rb25det bov and a gtr one in the shed, but obviously we need to see your setup so we can give you advice.