I didn't say it was bad.
But when we're talking about 170mph+ aero matters. An off the shelf 3.6l turbo swap is not going to be getting a 914 chassis up to those speeds to my way of looking at it.
BTW, just by way of gratuitous self promotion here, one of our gearboxes recently set a record on the Fontana Roval. 175mph and they hit the rev limiter because we geared it just a touch too short.
http://www.youtube.com/watch?v=bw6rYNPxrIk