Yes the running gear is the same as far as I am aware and i know that the RS is 300 as std however I didnt know how far you could push it...

Was made aware that the box on the ST and RS is not the best, think Ford may have been concerned about putting more power to it and more boost.... However when I spoke to Mr Goode himself he said they had some STs running 400+ with no problems.

Whats the most bhp out of an ST or RS in existence? I see there are some at 400+ but are there any higher?