Original sentence: Construction retained the traditional split between chassis and body, which facilitated the provision of special bodied versions though in practice the overwhelming majority of cars were delivered with the standard steel body shell, produced by Pressed Steel, and combined with light weight aluminium based alloy used for the doors, bonnet/hood and boot/trunk lid.External dimensions were slightly tweaked, the interior remodelled, the weight reduced by a little over  and improvements to the engine boosted speed and performance slightly
Edited sentence: Construction retained the traditional split between chassis and body, which facilitated the provision of special bodied versions though in practice the overwhelming majority of cars were delivered with the standard steel body shell, produced by Pressed Steel, and employing light weight aluminium based alloy for the doors, bonnet/hood and boot/trunk lid.External dimensions were slightly tweaked, the interior remodelled, the weight reduced by a little over  and improvements made to the engine which included fitting 2 inch SU carburettors in place of the 1¾ inch units used on the Series II Silver Cloud.Increased power and weight reduction boosted speed and performance slightly.Rolls-Royce, as before, refused to disclose overall engine power output, but indicated that there had been an improvement of "perhaps 7%".The compression ratio was increased to 9:1, reflecting the higher octane levels of premium fuel in major markets