I agree with Finn.  I read someplace (that appeared credible) that you could
loose 20% of your cooling with leaks totaling less than 1 sq inch - easy to
get with a small hole here and there.  Don't know how accurate that figure
is , but the thought is there - plug all leaks.

Ed

Notice the silicone filled holes for the Tye wraps and around the hood pin washer. The coolers are sitting on soft foam strips. The whole top cover of the radiator ducting is removable and held down with Dzus buttons. It is sealed with foam strips. The ducting side and bottom sheets are glued to the radiator with silicone.

It is all required in order for the radiator to work. 

 

At night, with the shop lights out, shove a trouble light up into the ducting. If any light is escaping from other than the fins, it needs to be sealed off. 

 

Lynn E. Hanover