WORKING for Street Machine means we see just about every kind of engine swap, with Barra and LS mills in particular getting thrown into just about everything short of your mum’s dishwasher.

Photos & video: Rob Read

One way to stand out from the crowd is to use a late-model Hemi donk, and the spiciest version of the lot has been shoehorned into this unsuspecting 2016 Chrysler 300 SRT by Lee Forward and his crew at Dontex Automotive & Performance in Melbourne.

They’ve ripped out the 470hp 6.4-litre Hemi V8 and replaced it with a much gnarlier, 6.2-litre, 840hp supercharged Hemi V8 from a Dodge Challenger Demon.

The Demon was the even more bonkers version of the internet-breaking Dodge Challenger Hellcat, which originally debuted with 707hp and enough torque to destroy the rear treads before you’d even left the showroom car park.

The Demon took that a step further, with a larger 2.7-litre blower over the Hellcat’s 2.4-litre item, a beefier camshaft, stronger pistons and rods, and an interchiller system exclusive to the Demon that helps keep those intake temps nice and mellow.

Even with a quoted 840hp from the factory, the boys at Dontex didn’t just drop in the Demon mill in standard from. They ported the blower, bolted on a 105mm throttlebody and changed the blower belt system to a 2.85-inch upper pulley and 10 per cent overdriven lower pulley, yielding 22psi. They also used a JLT cold-air intake along with an uprated fuel system sipping E85.

The head-kicking result was a peak figure of 960rwhp on the hub dyno. The boys are hoping to run a high eight or low nine-second pass at the drags, which would be an impressive feat given the 300 is still fully loaded at nearly two tonnes. We’re looking forward to seeing what this thing can do in the near future, and we’re also getting super-excited to slam our own 6.4-litre Gen III Hemi into our Carnage VE Valiant wagon project in the coming months.