You may be somewhat disappointed to know that the Mustang fitted with 4 Hispanos was also powered by the Allison engine, rather than the Rolls Royce engine. Designated as the Mustang Mk.IA by the Brits, it lacked high altitude performance, but was relatively fast on the deck being able to touch 360 mph near sea level.
I doubt it would require perking.
My regards,
Widewing