From lifelineambulances.com:

Reference #: 4532
Model: Superliner Type I
Dealer: Jefferson Fire & Safety
Module Size: 167″
Headroom: 74″
Chassis Make: Dodge
Chassis Type: 5500
Wheel: 4WD
Air Ride: Liquid Spring
Type I ambulance on RAM 5500 chassis

Life Line Emergency Vehicles photo

Type I ambulance on RAM 5500 chassis

Life Line Emergency Vehicles photo

Life Line ambulance interior

Life Line Emergency Vehicles photo

thanks Martin