604 RPM range ?

[Lazer-10]

What is the best RPM for a 604. Looking to make motor last but still have plenty of power
Thank you in advance

[Egoracing]

Several factors come into play but just for numbers. Our first 604 liked 6400RPM and ran best there, the second one we had seemed to run better at 6800. I would NOT advise running over a 6800 chip.

[cassellracing24]

Ego, was this due to the Later heads having better casting's maybe ???
After mid 07 I belive...

[Egoracing]

Never thought about it but it was a newer engine, I believe it was a late 06 or maybe an early 07 engine.

[BTDT]

We have an 08 604 with 80 laps that had an RM bolt (yes GM did do it). The car had a 7000 chip in it. During tear down valve train damage was found from possible over revving (chip off the seat of the exaust valve no other damage. replaced seat. According to Steve Hendren never turn over 6800. We now have a 6800 chip.

[sikjeep]

I run 6450, with a 6800 chip, runs great