Art,

 

Both Positech and Aero-Classics make coolers.  But I think Aero-Classics is a superior product.  You can call Pacific Oil Cooler and request a quote or use their e-mail quote request form.  Buy the "G" style cooler based on Niagara TCM part # 654580, Aero-Classics part # 8000440

 

 

Ram aircraft also sells the Aero-Classics coolers.

 

 

I know of one guy who made the air duct to push more air over the cooler and it worked pretty well too.

 

Mike