No idea what the bhp increase is but wild chip made a big difference on my motor, much better throtle respose and felt a good bit more pokey.
Be patiant though, these chips are made to order i think.
How about coming along to the next surrey meet on the 8th when its all fitted?
mine took about a week and a half (If I remember right). Well worth the wait, it got rid of that annoying 325 flatspot near tickover when pulling away gently, and cut the 50 - 80 time in 3rd from 7.8 to 6.7. Much easier to drive now, a lot smoother, and less jerky