Al has a high coefficient of thermal expansion (it expands a lot when heated) compared to steel. The knock on effect might be that coatings on it that are not as "flexible" and could crack. I doubt if a60 deg temp rise will be an issue though. If you are worried then stick on some self adhesive heat reflector to the wing inners to further reduce the temp. they get up to. Same for any chassis areas close to the cat/exhaust. Agriemach (DaveW uses them if i remember his posts) supply good stuff.
