of a cross-ram intake manifold tuned for peak power above 4000 rpm and two Carter AFB-3447SA 4-barrel carburetors. The Max Wedge also included high-flow cast-iron exhaust manifolds that, on the later versions, resembled steel tube headers. The Max Wedge was factory rated at (depending on compression), and at 4400 rpm. Before the end of the 1963 model year, Chrysler introduced the Stage II Max Wedge with improved combustion chamber design and an improved camshaft. The last performance year for the Max Wedge came in 1964 with the Stage III. The factory-advertised power rating never changed despite the Stage II and III improvements. A 426 Street Wedge block was also available in 1964 and 1965. It bears little relation to the Max Wedge except for basic architecture and dimensions. The Street Wedge was available only in B-body cars (Plymouth and Dodge) and light-duty Dodge D Series trucks. It was an increased-bore version of the standard New Yorker 413 single 4-barrel engine. 440 The RB was produced from 1965 until 1978, making it the last version of the Chrysler RB block. It had a light wall construction, precision cast-iron block, with iron heads and a bore of , for an overall displacement of . From 1967 to 1971, the high-performance version was rated at ( in 1971) at 4,600 rpm and at 3,200 rpm of torque with a single 4-barrel carburetor, and from 1969 to 1971, the highest-output version had an intake setup with 3X2-barrel Holley carburetors ("440 Six Pack" for Dodge, "440 6-BBL" for Plymouth) producing at 4,700 rpm ( in '71) and at 3,200 rpm of torque. In 1972, changes were made to the horsepower ratings of vehicle engines from gross (engine only, without air cleaner, exhaust system, alternator, or other power-consuming components) to net (with alternator, air cleaner, mufflers, and other vehicle equipment installed). The new rating system produced lower, more realistic numbers for any given engine. At the same time, emissions regulations were demanding cleaner exhaust. Engines including the 440 were made with reduced compression, modified cam timing, and other tuning measures to comply with the newly tightened emissions regulations. The 1972 440 produced (gross) at 4400 rpm; the new net rating was —which very closely coincided with period German DIN ratings and TÜV measurements. The high-output 440 (4-barrel/mild cam/dual exhausts) was marketed as the Magnum in Dodges, the Super Commando in Plymouths, and the TNT in Chryslers.