Hey Brook! What cam is it?
If the springs are rated to 6500, that’s a good thing. Is you know according to the manufacture that valve float will happen at about that RPM, you know where to let off. After that, valve control may become an issue. Since max RPM is a function of ether or both the springs and the cams profile. (AKA What the duration is cut for RPM wise.)
Most builds of this type your doing find max power on and around the cams profile are now limited to the heads flow capacity. Since the heads are stock, this will be around the 5800 mark. There could be a 200 RPM + or - here. Cam profile dependent.
Most racers will find best ET’s shifting past peak power at some point. This a variable mostly based on bore and stroke combo along with the cam and spring package and the heads ability to flow air.
Post the cam specs or card. It’ll give us all a better idea of what the engine may do.
