ALL GC8 rods were shite.

Block is good for 500whp but the internals aren't.

Later blocks had better rods but for anything over 350whp you really should consider forged internals. They can cope with more but its a game of roulette.

For example My JDM MY05 had an unopened engine and run 504bhp (flywheel) so it can be done but if you want to be absolutely sure of it not shitting itself above 350whp then it needs to be forged in my humble opinion.

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605whp
Quarter Mile in 10.9 seconds @ 135mph /217kph
0-100 kph 3.2 seconds