605ci Hemi-powered Dodge Challenger

Drag Challenge veteran Jon Mitchell aims for the nines with his 605ci Hemi-powered Dodge Challenger

Dodge Challenger
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JON Mitchell was there from the beginning. He was lucky enough to ride shotgun in one of the 18 cars that contested Street Machine’s very first Drag Challenge in 2014. “I went with Steve Reimann in his Dodge Dart, and I’ve done every Drag Challenge since,” he says.

First published in the August 2021 issue of Street Machine

That first DC experience caught Jon hook, line and sinker. At the time, this 1970 Dodge Challenger was at home in his garage, still mid-build. “It really inspired me to finish the car and get it ready for the following year,” he says.

Street Machine Features Jon Mitchell Dodge Challenger Rear Angle
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True to his word, Jon and his bad-arse Challenger were front and centre for Day One of Drag Challenge 2015. Under the hood was a 512ci Wedge motor that was tough enough to push the hulking beast to 10.50s. But the car didn’t come out of the event unscathed.

“We destroyed a tailshaft uni,” says Jon. “We moved heaven and earth to get it fixed – which we did. Unfortunately, by the time we got going again, we missed out on making a pass by about an hour. Still, we finished the week and had a great time.

Street Machine Features Jon Mitchell Dodge Challenger Front
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Even pumped up some 3in, the one-off fibreglass hood isn’t quite able to contain the mountainous tunnel-rammed Hemi

“The next year, I managed to just get past my good mate Andrew McLellan by 200ths of a second to take out Quickest Mopar and grab Runner-Up in Outlaw Aspirated.”

Unfortunately, 2017’s DC was not as kind to Jon. “We dropped a lifter and got stranded in Ararat, Victoria,” he recalls. “During the rebuild afterwards, we added the tunnel ram.”

Street Machine Features Jon Mitchell Dodge Challenger Side
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This helped the car run a 10.59 best at Drag Challenge 2018. Jon was running third in Outlaw Aspirated until the fuel pump let him down, relegating him to fourth. Still, he did pick up Quickest Mopar for the second time. But he knew it was time to step things up a bit.

“I hurt the motor again after Drag Challenge 2018, and was looking for parts to make the Wedge a bit tougher,” Jon says. “I rang Peter Gratz to see if he had any Wedge stuff. ‘Not much,’ he said, ‘but I do have this Hemi sitting there.’”

Street Machine Features Jon Mitchell Dodge Challenger Engine Bay
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With an aluminium, 605ci Indy Maxx Hemi up front, it’s little wonder the Challenger was the NA big-block dyno champion at Chryslers On The Murray in 2020. But the car is far from all go and no show, placing in the top five at Chryslers On The Murray 2018 and winning Top Mopar and third Top Muscle Car at the All American Day in Sydney 2016, among many other trophies

A 605ci Indy Maxx all-alloy Hemi, in fact! “Well, I started to drool,” Jon laughs. “I always wanted to put a Hemi in it – it’s the real reason I bought the car. Besides, Andrew was stepping up his ’Cuda to run sub-10s, and I didn’t want to get left behind.”

Jon and his brother-in-law, Howard Knight, jumped in the ute and drove from Sydney to Brisbane to pick up the new acquisition.

Street Machine Features Jon Mitchell Dodge Challenger Boot
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Howard was kinda compelled to make the trip, as he was partly responsible for Jon owning a Challenger in the first place. Jon remembers the pair cruising home from Chryslers On The Murray in Jon’s stout E55 Charger and deciding between them that a 1970 Dodge Challenger would be the next project. As fate would have it, Steve Reimann just happened to have a ’70 Challenger that had received a full rotisserie respray in Plum Crazy paint. Although it was just a shell, Jon snapped it up when it was offered it to him.

The original plan for the car called for an orange exterior and stark white trim. However, given the shell’s fresh paint, a colour change was quickly ruled out. Jon did, however, convert it to RHD as part of its metamorphosis into a quarter-mile missile.

Street Machine Features Jon Mitchell Dodge Challenger Interior Front
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The pistol-grip slap-stick shifter is connected to a radically upgraded, reverse-pattern Torqueflite 727 three-speed auto. The seats are the factory items, although Jon says his missus wouldn’t mind some heated pews!

Fast-forward to the run-up to Drag Challenge 2019, and Jon and Howard had just a couple of short months to shoehorn the newly acquired Indy Maxx into the front of the Mopar. And I do mean shoehorn, as the Maxx has a one-inch-taller deck height compared to the already girthy Wedge. Indy makes a special rocker cover to help the mill fit into an E-body, but even after modifying the TTi headers, Jon still only had about 12mm clearance on each side.

“It fought me all the way,” he says. “Because of the external KB oil pump, we had to modify the sump and all the lines. But with loads of help from Russell at Dominator Engines and bit of ball-peen hammering, we made it.”

Street Machine Features Jon Mitchell Dodge Challenger Seats
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The Challenger ended up being the first car down the track at Drag Challenge 2019. Jon staged the car, took the green, stomped the throttle – and promptly grenaded the Torqueflite 727. “It was my fault,” he says. “We rushed it. The trans was never built for this engine, but I thought it could handle it. On that very first hit, it cracked the rear housing and turned the converter into a cement mixer – yet still managed to run a 10.22@137mph!”

Peter from South West Automatics stepped up to piece together a tougher, stouter ’box. With that sorted, Jon is now eyeing more upgrades, including an AlterKtion front end with coil-overs and a full rollcage, before getting the car teched for 8.5s. Jon’s aim is mid-to-low nines, so hopefully soon we’ll finally get to see what his wicked Hemi-powered Challenger can really do.

Street Machine Features Jon Mitchell Dodge Challenger Shifter
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And just to ensure Jon doesn’t get bored, he’s also in the final throes of an HQ coupe build. “I’ve painted it the factory Lone O’Ranger orange and it runs a tough small-block and nine-inch,” he says. “It’ll also have a five-speed manual. Should be a fun car!”

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LIKE FATHER, LIKE SON

TOUGH cars have been in Jon’s blood from the start. “My dad, Michael, had an XA GT that he built up to Phase IV specs,” he says. “He also had a GTHO Phase I – the MM061 number plates on the Challenger came from that car. Back then, you could order the letters but not the numbers, so these were the 61st personalised plates issued in NSW.

“As a five-year-old, I can remember going to Brickies, and have since done a bit of street racing myself in a Walkinshaw Commodore with a pair nitrous bottles in the boot.

“I’ve owned a heap of other tough cars: Monaros, GTs, L34s, XU-1s, a Nissan GT-R and an 11.0sec E55 Charger, which I recently sold. I even had a full-on blown Camaro, tubbed with wheelie bars. None of them got anything like the attention the Challenger gets.”

Street Machine Features Jon Mitchell
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JON MITCHELL
1970 DODGE CHALLENGER

Paint:  PPG Plum Crazy
ENGINE
Brand:  Aluminium Indy Maxx Hemi 605ci
Inlet manifold:  Tunnel ram
Carbs:  Twin 1050 Pro System
Heads: Indy CNC-295
Camshaft:  Solid-roller, 690thou lift
Pistons:  JE forged, ceramic-coated crowns, Teflon skirts
Conrods:  Oliver
Crank:  Callies
Sump:  External pick-up
Oil pump:  Keith Black
Fuel pump:  Aeromotive 1000
Cooling:  Alloy radiator and twin thermos
Exhaust:  TTi 4-into-1 headers, 2½in primaries, 4in collector, 3in system
Ignition:  MSD Billet distributor, programmable 6AL-2
DRIVELINE
Gearbox:  Torqueflite 727 reverse-pattern
Converter:  5700rpm stall
Tailshaft:  Strange, 4in billet yokes
Diff:  Strange Dana, Detroit Locker centre, 4.11:1 gears, Strange axles
SUSPENSION & BRAKES
Front:  90/10 shocks, Commodore rack-and-pinion
Rear:  Calvert split mono-leaf springs, adjustable Ranchero shocks, CalTracs
Brakes:  Wilwood (f & r)
WHEELS & TYRES
Rims:  Convo Banshee; 15x7 (f), 15x10 (r)
Rubber:  Nexen N Blue 205/70R15 (f), Mickey Thompson ET Street S/S 295/65/R15 (r)

THANKS
Russell at Dominator Engines; Howard Knight; George Shalala at Shalala Smash; Peter at South West Automatics

Craig Parker
Journalist
Matthew Everingham
Photography

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