8500 rpm possible by stiffer valve springs?
 

Is 8500 rpm attainible with stiffer valve springs in the lx Dohc motor not that i would want my car to rev that high and get no lo end torque but is it possible if so what car would you be able to find stiffer valve springs from.

That all depend on the cam profile you choose, you select valve spring stiffness based on the cam profile you choose. With stock cams don't go above 8000rpms since valve get's unstable at those speeds due to it's cam profile and OEM valve springs stiffness.

also concider rotational mass. if you are looking for a really high all motor set up with a high rmp research lighter internals, cam regrinds, i know a guy who does a great job and lives about 2 hours away from me.

Would the rods handle those kids of engine speeds? Not too many stock rods can handle RPMs like that.

I have to agree that you'd more than likely need aftermarket internals.

THey're strong rods, they should be able to handle it.