if you wanna twin your 7m its going to take more money than you wanna put in to it. if you want twins that bad just save the money for a 2jz. its a true tiwn, i think this means one turbo is small(youll hit boost really fast in the low down rang) and the othere turbo is a lil bigger to keep maken power in the high rpms. and for a build on the 7m motor, its not had stock pistons and robs are good for 500 to 600 hp. now running that for a long time i dont know about. so if you want good power and have a better chance of it not messen up on you, there are jp pisons, wisco, ross, all good ppl to get pistons from. but back to the main post, one turbo that is set up for the hp you wanna make it the best. and when i say a turbo that is set up for the hp you wanna make, i mean there are thing called turbo maps or compressor, every turbo comp. should have one. just look in the middle to see what its effectance is at what rpm and so on. google it or post a Q on here about how to read a turbo map.