In 1956 Maxon began offering 342 CID (about 5.6 liters) and 367 CID (about 6.0 liters) options for the M Series. In addition to more displacements to choose from, Maxon began offering a high performance package for their M Series, featuring stronger, yet lighter forged internals, triple 2 barrel carburetors, and a lightweight, high performance exhaust system all as standard options. Customers could opt for a quieter exhaust system with the Plus Package just as they could with the standard M Series models, but instead of a third 2 barrel carburetor, customers could request 4 DCOE carburetors to be installed in place of the default triple 2 barrel configuration. Contact Maxon Motors for more details or to place your order (PM me).