The final stages of Gen3 engine development are underway, with the engines now undergoing testing Stateside.
The engines have been taken to the United States for durability testing.
The testing sees the engines approaching their final specification.
Ongoing calibration work has continued, both on the track cars and local dynometers.
Both engines have proven to be highly reliable in testing, with both cars completing over 4000km.
The engines will be put through the wringer in the US as Supercars closes on final specifications.
They will be put through programmed simulations on advanced dynos, and will complete up 10,000km.
Testing on the 5.7-litre General Motors and 5.4-litre Ford engines got underway late last year.
The likes of water, engine oil and transmission cooling have been signed off and are in production.
The prototype Camaro and Mustang were taken to Sandown last week.
Sandown became the ninth different circuit to host Gen3 track time.
There, the revised front-end, which was run in the Camaro, passed with flying colours.
From there, the prototypes will be taken to Bathurst, where they were first revealed last December.
KRE is building 28 race engines, or two per Camaro.
Herrod Performance Engines, meanwhile, is leading Ford's engine programme.
“The plan is to get 10,000km on both engines,” Supercars Head of Motorsport Adrian Burgess told Supercars.com.
"All the parts are in shipment at the moment. From there, we’ll go into the build of the race engines.
“If any issues arise during durability testing, we might make very minor changes.
“But to now, they’ve run smoothly and we’ve put plenty of miles on them.
“We won’t be designing any new blocks or heads, or anything like that.
“We’ll be into engine build on a larger scale in the coming weeks."
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