Engine problem... yet again

[Ez-Bone]

I guess I may be forced to just rip the engine out and overhual it anyway despite trying to kind of avoid that so soon.

Problem I'm having is just last night, I took the car out for a spin and to stretch her legs. Well, the few times I really got on it, strangely enough; it wouldn't redline. However, it would stall around 5k RPM and become gutless which really has me worried. I guess I'm just panicking but can you blame me?

There is also a 'clunking' noise at idle but goes away when under load or revved up past 1.5k RPM. All my fluids are proper and topped off so it shouldn't be that. I thought 'possibly' that my sensors were too close to the flywheel and are possibly bumping. I don't know, I'm kinda panicked here.

What could be going on