If there is one person who could shed more light on this it would be Bill Eaton, he was the guy that lengthened the coupe chassis to accept the alloy 390 and was apparently sent back to the shop to fetch another tail section for this car on the day of the accident. Funny how those 58mm webers seemed to be everywhere Miles & Eaton went, which makes me wonder if this car had the alloy 390 motor as well although the fuel lines are fitted in a different manner than those in the coupe.
Due to a series of coincidences I have a specific interest in the Alloy 390 and all the cars it was associated with, hence my 'knowledge', which only comes from reading books and being fortunate enough to talk with some people who were involved with some of these projects.