I'd say there's no need to move the engine back.
I've just been for a blast in mine with its huge, cast iron six sitting over the steering rack and the handling is very neutral and really confidence inspiring. Surprisingly good, in fact, considering it's been set up by me by eye.
Unless you're looking for a competitive track day car where every thousandth of a second counts I wouldn't lose any sleep over where the engine sits in the chassis. After all, Phil and Barry are putting in similar lap times to Porsche 911's in theirs.
