use in full-size models, and it eventually became the best known of the Slant Six engines. The original Chrysler 225 Slant Six produced around at 4,000 rpm and of torque at 2,800 rpm. In 1982, Chrysler signed an agreement with Perkins Engines to build a dieselized version of the 3.7, with seven main bearings and turbocharged as well as naturally aspirated (and also of the 2.2-liter inline-four) in Windsor, Ontario. Design work had started in 1975, but with the collapse of the diesel market in North America, these plans were cancelled in 1983. Aluminum block 225 Between late model year 1961 and early model year 1963, approximately 52,000 die-cast aluminum RG blocks were produced and installed in passenger cars. These open-deck blocks used integrally cast high-nickel iron cylinder liners, and bolt-in iron upper and lower main bearing caps. Internal components (crank, rods, pistons, etc.) were the same as used in the iron engine, and an iron cylinder head was used with a special copper-asbestos gasket. The aluminum block weighs about less than the iron RG block. Although serviceable examples can still be found, the aluminum RG tended to undergo delamination between the iron cylinder liner and the surrounding aluminum. Severe corrosion within the block is also commonly found because of the general tendency in the 1960s and 1970s to fill cooling systems in summer with plain water without corrosion inhibitors. Moreover, the open-deck design and primitive head gasket technology are not sufficiently robust to withstand the increased seal demands of increased compression or forced induction. High-performance variants Most G-engines were equipped with small-capacity carburetors (such as the ubiquitous Holley 1920) and exhaust systems adequate for standard passenger car usage at low altitudes, but which tended to hamper maximum available performance at high altitudes, in heavy or race-purpose vehicles and/or where quicker acceleration was desired. To meet the demand for improved responsiveness, modified engine configurations were made available in various markets over the years. Hyper Pak The Hyper Pak was a parts package made available from 1960 through 1962 at Chrysler Corporation dealer parts counters. The parts were made available to comply with the regulations of sanctioning bodies for racing events in which Valiants had been entered by factory-backed teams: All parts used had to be "stock" parts, the definition of which meant that they were available through normal factory parts channels. The Hyper Pak consisted of a very-long-ram intake manifold