i've been trimming the front tinwear piece to get it to fit in my 36hp engine bay - how sealed does it need to be - i assume as sealed as possible, but it's 'heavily' modified and their are gaps.
The better the seal is, the more exhaust heat you're going to keep out of the engine bay. Small holes shouldn't make much of a difference as long they are few. I will put my hand up and admit that my engine bay seal is perished. I am not having overheating problems although I do know that it isn't good for it. Does get a big toasty in engine bay with gap there. 🙅