I have to ask why you'd need boost with a 2.5? You're at the limit of the speedo in terms of motor, none of the speedos claim that you can add boost when running 2.5 so I'd be careful.
I'd ask in the Tekin thread here and see what Randy comes back with.
P.S. Post up a video when you do try it, I'd love to see how it compares with nitro
