I looked into having ITB's fitted to my R400(Roxy) in 2019 and much consideration and research, i ended up going to Luke Stevens in East Anglia, bit of a treak from the North West but well worth the effort. Roxy suffered with the usual R400 problems of poor low RPM running, with the added issues of cracks in the standard inlet and ultra light flywheel, this made pulling away a but of a hit and miss affair. Luke ended up recommending "Jenveys" and a full remap, i was EXTREMELY concerned over the work involved, especially cutting Roxy's bonnet but all i can say is I'm absolutely delighted in the work. The car has been transformed, sounds amazing and with the added bonus of a few extra ponies, and the overall cost was around half of the similar CC conversation.