Oh Boy! I've made an Aztec powerpack work in a Cruisemaster! Actually, I used an Aztec powerpack base to repair a Cruisemaster powerpack. The Piper powerpack, as it is configured, will not fit under the seat of the Cruisemaster. It uses a different, taller pressure relief valve from the Cruisemaster version and the short dome of the Cruisemaster powerpack will not fit over it. The base must be machined so the Cruisemaster relief valve can be installed and then the short dome can be installed.