Daniel,
In my opinion you should leave the engine fan in place. I took it off on my Spitfire and can honestly say the performace was exactly the same! Apart
from when the head gasket blew

I have opted to leave it exactly where it is on the TR6 as I am willing to 'sacrifice' 1bhp to know that my engine will not be overheating! It's not as
if Stag engines already have a bit of a reputation for overheating or anything is it?
As for the hood - what's the condition of the rubber seal to the header rail? (Assuming it's the same as Spitfire, TR6 etc). If this is worn this would
make the levers too loose. i.e. With a new seal on my car, it takes quite a bit of effort to lock the levers in place and they stay there!
Regards,
Michael.