2" is insufficient room for cooling above most amplifiers! For a space that restricted I would use a fan for cooling. You need a good 10" to a foot above the amp- otherwise even though the heat might not trip the protection, the amp will be running warmer and things like filter capacitors really don't like that- they will have a shorter life.
Adequate cooling is important for any power amplifier.
Adequate cooling is important for any power amplifier.