Hi Russ
I have just had a quick measurement of my chassis.
The width between the inside of the side rails & the transmission tunnel is proximately 450mm.
Got shot of a very nice set of Cobra seats due to the width, If only I gave it some better thought.
Probably could have made the transmission tunnel a bit narrower to allow the fitting of a slightly wider seat.
That said, those Two Cobra seats weighed nearly as much as the bare chassis
