one more thing...as for cost, unless you are a terrific welder, pipe bender, fabricator a TT set up is going to cost more than a roots or even a Centrifical unit. By the time you get a fuel managment system, EFI, (and trust me you're not going to push 14 psi down a carb) the turbos, cooler you will have a bunch of time invovled. It's either cut the hood or the innner finders. I did a lot of work on this myself and I have about $2500 in my set up. A brand new 671 out of the box w/ all the hook-ups can be had for about $2800. Much easier to install and much easier on the carb(s) You can find used/re-manned units on 'bay for 1/2 that. So what's cost more cost effective?