Basically used a Nissan engine and transmission and dropped it into a Commodore. There were a few compatibility issues, especially with overheating and blown head gaskets. Rust around the windscreens was fairly common as well.
Overheating engines
Lifter failure
Exhaust manifolds breaking and blowing gaskets
Exhaust leaks
V8 rocker gear failure
V8 rear main seal leaks oil
V8 fuel filter
V8 rough idle
Broken power button
Thin/ warping disc rotors
Handbrake button stays in
Tail lamp electrical earthing issues
Indicator stalk issues – Indicators not turning off automatically after corners
Crank angle sensor failure
Noisy starter motor
Calais eyelid failure
Fuel pump failure/ seizure
Diff arm bushes wearing out
Steering rack issues
Dash control switches breaking
Rust around front and rear windscreen
Water seeping into headlights
Water leaking through front windscreen
Odometer can stop working
Worn ignition barrel – Eventually means car can be started without a key