Heat is not an issue, we regularly get 40+ degree days here in Australia and our test engine is installed in a heavy bus loaded with camper gear. We’ve never had an issue with overheating. We always recommend that an external oil cooler is fitted to help manage il temps. As with any performance upgrade – the engine can generate more heat so you need a way to get rid of it.
If you are concerned about heat why not consider fitting one of our crank fired distributorless ignition systems. These will automatically retard the timing when inlet air temperatures exceed the programmed limit