R - you'll have to go with Unit5302 on the 400+ horses deal, - the whole syatem has to go in line with each other ie. brakes, suspension, frame strengthning and tires -
when the system is built as a "together setup" - there should be no problem - need ZR cross tread type high performance tires, stabilizer systems, panhards, good springs and struts, and probably 13" to 14" two channel, 3 piston brakes ventilated.....like the ones coming out on the new Shalby500GT - actually, the new Shalby500GT is a good example of a performance design for 400+ hp.....i would have to do more study before i would jump into any design for that kind of performance - because making the right choices should make your ride streetable and a performer at the same time - hope this helps