I’ve heard via the grape vine that the standard box will not take much more than 350BHP. I’m running 375BHP on my standard box, and all is OK so far. But saying that, I don’t do any silly launches, and I do have a big tooth Quaife box sitting in the garage for when I get round to fitting it. I got all my parts from Graham Goode Racing for my 375BHP conversion, and did all the work myself. Once finished, I took it to a rolling road for setup to the check the fuelling/boost etc. I’m very happy with the way the car performs. Every body seems to have their own preferred tuners, so I’m sure someone will recommend another tuner. As for cost, it’s very difficult for me say, as I did a lot more work than what was necessary for the 375BHP conversion. I had the engine re-bored new pistons, crank reground etc. etc.

Have a look around the web site : - www.grahamgoode.com

Hope this helps.

Cheers
John