408: A lot of heat coming through the firewall.

[Barrie]

I had the same problem with a Jensen CV8 with a 6.3 engine. Apart from fitting heat insulators under the carpet I also had the exhaust wrapped in heatproof tape. (You can do the manifolds as well) This keeps down the air temperature in the engine bay.
Also I installed a Delta fan controller which prevents the engine from getting too hot in the first place. Auto Cooling Additionally it dealt with the occasional fuel vaporisation problem on really hot days and must help to provide desirable cooler air to the carb intake.
Try Summit for parts and advice https://www.summitracing.com/
Let us know how you get on.