American tuners??? can I remind you that no one tunes engines like us, look what we did to the Buick engine of 1963, it started as a 3.5 litre 135bhp and went on to TVR and 5 litre and 340bhp. It even became known as the Rover V8, so I feel that they could let MG-R do the tuning and we could see some interesting bhp figures.
i'm as patriotic as anyone but when it comes to tuning and V8's in particular,then the yanks are the "daddies".
when the ZT400 is available both sides of the pond i'll bet they will be the first to crack 700bhp