2 of mine had 3.6 litre conversions ..... 12 valve models...
D reg Late REV A, and an F reg Rev B, the Rev A was the quicker, more nimble of the two, but the Rev B was So solid and assured it made up for not being quite as quick out the gate, by being more composed and smoother through the bends....
slightly better top end on the B as well due to gearing...
and not really any thirstier under normal use than the std lump
I assume then Max, that both of these cars you speak of were Irmscher 3.6L 12v conversions? If these are Irmscher vehicles, Were these cars full Irmscher conversions with complete Engines, Suspension, Interior and Bodykit or just increased capacity engines??
Anychance of some more details about your 3.6L cars please Max?