Ok peeps, just a quick couple of questions

1) Whats the difference between the brown (RST) Amal valve, and the black cossie (webber) one? Are they interchangeable between cars? My mates 4x4 Cos was mapped at MSD on a brown one, and has been fine until the Amal valve failed, now we have swapped it out for a black on, it's boosting oddly, and dropped 4psi off peak boost. All the jets were transfered across.

2) How involved is fitting an air injector in place of the amal valve? Does it need a re-map or just a set-up and tweek?