Well, the engine is gonna be around 180, no matter how hard you do or dont run it. The engine/gear are huge heat sinks, no way around it. More cooling for them wont make a difference. Insulating the ER will help, IF, you can move the hot air out. If not it just migrates thru to the cooler living area, funny thing about heat, it goes toward the cool
Big fans, inny and outy, help tremendously. I use 8, 10 inch automotive type radiator fans in my sporty. It has 8v92 DDs, 5000 lb heat sinks. 4 fans are pulling air in, 4 are blowing air out. My aircons dont have to work as hard now.