Humming Hemi, 5.7L Hemi V-8 compression 9.6 to 1. 345 HP 375 Torque Dodge Hemi truck, I haven't seen this much excitement about a truck engine in decades. It's ironic that it's a 5.7L as GM phased out the most popular engine of all time.

Ford has High Swirl Combustion and GM has Vortec. And Dodge Hemi's in trucks have a great intake mixture system also but no one has a hemispherical head.

HEMI® Milestones  Updated through 2007 bottom of this page.

1939 Chrysler begins design work on first HEMI®, a V-16 for fighter aircraft.
1951 Chrysler stuns automotive world with 180 hp HEMI® V-8 engine.
1951 Chrysler New Yorker convertible paces Indianapolis 500 race.
1951 Saratoga first in Stock Car Class; second overall in Carrera Pan-Americana road race.
1951 Briggs Cunningham chooses HEMI® engines for his Le Mans race cars.
1952 A special HEMI® is tested in a Kurtis Kraft Indy roadster; it's banned by racing officials as too fast.
1953 Lee Petty's HEMI® Dodge wins five NASCAR races and finishes second in championship points.
1953 Cunningham's C-4R HEMI® wins 12 Hours of Sebring and finishes third at Le Mans.
1953 A Dodge HEMI® V-8 breaks 196 stock car records at Bonneville Salt Flats.
1954 A Chrysler HEMI® with 4-barrel and dual exhausts makes 235 hp.
1954 Lee Petty wins Daytona Beach race in a Chrysler HEMI.
1954 Lee Petty wins NASCAR Grand National championship driving Chrysler and Dodge HEMI®s.
1954 Cunningham HEMI®s win Sebring again, third and fifth at Le Mans.
1954 Dodge Red Ram HEMI® convertible paces Indy 500.
1955 Chrysler introduces the legendary 300 as America's most powerful stock car
1955 Chrysler "300" with dual 4-barrel 331 c.i.d. HEMI® is first production car to make 300 hp.
1955 A Carl Keikhaefer-prepared Chrysler 300 wins at Daytona Beach with Tim Flock driving.
1955 Chrysler bumps HEMI® to 250 hp in New Yorker and 280 hp in Imperial.
1955 Frank Mundy wins AAA Championship in Kiekhaefer-prepared Chrysler 300.
1956 DeSoto Fireflite HEMI® convertible paces Indianapolis 500.
1956 Chrysler 300-B HEMI® increased to 354 c.i.d. and 340 hp with dual 4-barrels.
1956 Buck Baker wins NASCAR Grand National Championship in Chrysler 300-B with 14 wins.
1956 Chrysler 300-B sets World Passenger Car speed record at Daytona Beach - 133.9 mph.
1956 Don "Big Daddy" Garlits begins 46-year winning association with Chrysler HEMI®s.
1957 Chrysler 300-C HEMI® increased to 392 c.i.d. and 375 hp.
1958 Last year of HEMI® engine in Chrysler 300 models.
1958 Don "Big Daddy" Garlits breaks the 170 mph barrier in his "Swamp Rat" HEMI® dragster.
1958 Chrysler 300-D HEMI® sets a Class E speed record at Bonneville at 156.387 mph.
1959 Original Ramchargers debut "High & Mighty" HEMI®-powered C/A (altered class) '49 Plymouth to win NHRA Nationals.
1964 A.J. Foyt wins Firecracker 400 at Daytona; Plymouths or Dodges lead every lap.
1964 Chrysler introduces the 426 c.i.d. race HEMI® into competition.
1964 Richard Petty debuts the 426 HEMI® and laps the field while winning the Daytona 500.
1964 Three HEMI® -powered Plymouths and a HEMI® Dodge sweep Daytona 1-2-3.
1964 HEMI®-powered stock cars win 26 of the 62 NASCAR Grand National races.
1964 Richard Petty captures his first of seven driving championships with eight wins, 37 top-five finishes.
1964 Don Garlits breaks 200 mph quarter mile barrier in HEMI® dragster - 201.34 mph in 7.78 sec.
1964 Jim Thornton wins 1964 U.S. Nationals in Ramcharger's "Candymatic" 426 HEMI® Dodge.
1964 Jim Paschal wins NASCAR World 600 at Charlotte Motor Speedway in HEMI®-powered Plymouth.
1965 NASCAR outlaws HEMI® by setting minimum production levels for street use.
1965 Bob Summers sets present 409.227 mph Land Speed Record in "Goldenrod" using 4 HEMI®s in tandem.
1965 Shirley Shahan becomes first female to win major NHRA event driving a HEMI® Plymouth.
1966 Chrysler builds the "Street HEMI®" and returns to NASCAR racing.
1966 Richard Petty again wins Daytona 500 in his HEMI® Plymouth Belvedere.
1966 HEMI® Dodge Charger wins the NASCAR Championship, Plymouth is second.
1966 Norm Nelson wins USAC stock car championship with seven wins in a HEMI® Plymouth.
1967 Richard Petty wins an incredible 27 Grand National races in HEMI® Plymouth; 10 in a row.
1967 Richard Petty wins his second NASCAR championship in his HEMI® Plymouth.
1967 Don White's Charger gives HEMI ® cars second USAC championship in a row.
1968 Sox and Martin win three major AHRA events; Ronnie Sox named AHRA Driver of the Year.
1968 Dodge and Plymouth produce a limited number of 426 HEMI® Super Stock Darts and Barracudas.
1968 Road Runner, first budget muscle car, is introduced by Plymouth; available with 426 HEMI® option.
1969 Dodge introduces Charger 500 HEMI®, which wins 22 NASCAR races.
1969 The "winged" 1969 Dodge Charger Daytona with HEMI® power reigns over NASCAR superspeedways.
1970 Buddy Baker is the first to break 200 mph on a closed course in a HEMI® Dodge Charger Daytona stock car.
1970 Bobby Isaac sets a closed course speed record - 201.104 mph - in a Dodge Charger Daytona after winning the NASCAR championship.
1970 Sox and Martin HEMI® Plymouths win 17 major championships and are runners-up in all other major events.
1971 Bobby Isaac breaks 28 records at Bonneville in a Dodge Charger Daytona; top speed is 217.368 mph.
1971 Richard Petty wins his 3rd NASCAR Grand National championship in a HEMI® Road Runner.
1971 Don Garlits introduces HEMI-powered rear engine dragster at NHRA Winter Nationals.
1971 Sox and Martin win six of eight NHRA events; they represent drag racing at a presidential reception.
1991 Al Teague sets 409.986 mph wheel-driven Land Speed Record in the Supercharged class with single HEMI®.
2003 5.7-liter HEMI® "Magnum" develops up to 345 hp and 375 lb.-ft. of torque.
2003 5.7-liter HEMI® "Magnum" in Ram 2500/3500 series trucks delivers best-in-class power, acceleration and towing capacity.
2003 5.7-liter HEMI® "Magnum" is 56 lbs. lighter, has 41% more power and 12% more torque than the 5.9-liter Magnum wedge head engine it replaces.
2003 5.7-liter HEMI® is the first Chrysler production gasoline engine with electronic throttle control or "Drive-by-Wire".
2003 The 5.7-liter HEMI® meets all federal emissions standards, delivers 8-10% better economy than the engine it replaces.
2003 5.7-liter HEMI® "Magnum" is the first Chrysler production engine to use two spark plugs per cylinder.
2003 5.7-liter HEMI® features "Leak Free" design with a cast-in drain through on the oil filter pad.
2003 HEMI® architecture produces power comparable to an overhead cam engine, yet is less costly to build.
2003 The new HEMI is named one of Ward's Automotive 10 Best Engines.
2004 The Ram 1500 and all-new Dodge Durango are available with 5.7-liter HEMI.
2004 The 5.7-liter HEMI is named one of Ward's 10 Best Engines for the second year in a row.
2005 After nearly 50 years, the HEMI engine returns to a Chrysler brand passenger vehicle in the new Chrysler 300C and, after nearly 30 years, to a Dodge brand passenger vehicle in the Dodge Magnum R/T, fitted with the 5.7- liter HEMI V8.
2005 HEMI-powered Chrysler 300C and Dodge Magnum R/T produce 340 hp (254 kW) at 5,000 rpm and 390 lb.-ft. (525 N*m) at 4,000 rpm.
2005 Chrysler 300C and Dodge Magnum R/T are the first modern, production North American vehicles to feature cylinder deactivation—the Chrysler Group Multi-Displacement System (MDS) turns off four cylinders in the 5.7-liter HEMI engine when V8 power is not needed for up to a 20% fuel savings.
2005 The Street and Racing Technology (SRT) team develops a 6.1-liter version of the HEMI to power future Chrysler Group SRT8 models—the 425 hp engine is the highest-rated specific-output naturally-aspirated V-8 ever offered by the Chrysler Group. Its 69.8 horsepower-per-liter rating exceeds even that of the legendary 1966 "Street HEMI." Torque is rated at 425 hp (317kW) at 6,000 rpm 420 lb.-ft. (596 N*m) at 4,800 rpm.
2005 The 6.lL HEMI engine has more displacement with larger cylinder bores compared to the 5.7-liter.
2005 The compression ratio was boosted from 9.6:1 to 10.3:1 for more energy in the combustion process.
2005 Engine breathing in the 6.1-liter was increased with new high-flow cylinder heads, a specially designed intake manifold and exhaust "headers" with individual tubes encased in a stainless-steel shell. Exhaust is routed through a 2.75-inch exhaust system.
2005 A unique camshaft profile maximizes power in the 6.1-liter HEMI.
2005 The Chrysler 300C SRT8 is the first two SRT8 products announced—both packing the new 6.1-liter HEMI engine.
2005 For the first time ever, a HEMI is available in a Jeep®—the all-new Jeep Grand Cherokee is available with 5.7-liter HEMI.
2005 MDS is standard equipment with the HEMI in Jeep Grand Cherokee—the first time cylinder deactivation is offered in a sport utility vehicle.
2005 The 5.7-liter HEMI is named one of Ward's 10 Best Engines for the third year in a row.
2005 The one-millionth modern HEMI engine roars off the assembly line.
2006 The all-new Dodge Charger R/T powers its way back to the streets and racetracks across America with 5.7-liter HEMI, paying homage to the musclecars of the '60s, and adding 21st century performance and functionality.
2006 The Dodge Charger Daytona includes a unique high-performance exhaust and induction system to allow the 5.7-liter HEMI to produce 350 hp (261 kW) with a distinctive throaty exhaust tone.
2006 Chrysler Group is the first to offer cylinder deactivation in a pickup truck—MDS made standard equipment with the HEMI 5.7-liter engine.
2006 MDS is added to HEMI-powered Dodge Durango.
2006 Chrysler Group MDS is standard equipment on Chrysler 300C and Dodge Magnum R/T, Charger R/T, and it is standard on 5.7-liter HEMI-powered Jeep Grand Cherokee, Jeep Commander, Dodge Durango and Ram 1500.
2006 The SRT lineup is expanded to now include the Dodge Magnum SRT8, Dodge Charger SRT8 and Jeep Grand Cherokee SRT8—all powered by the 6.1-liter HEMI.
2007 There will be nearly one million vehicles on the road equipped with Chrysler Group's MDS.
2007 With the addition of MDS to HEMI-equipped Dodge Durango and Ram, MDS-equipped vehicles through the end of the 2007 model year will save more than 60 million gallons of fuel each year.

Source:  The Chrysler Group/ www.WardsAuto.com