I don’t see a problem with the build for a torque monster street motor. I would not change the heads since you already have them. If you want more power start with head porting. That will give you the most gain with what you have.
Next I’d throw a victor intake on it. If you still want more after all of that throw in a solid roller cam.
You’re combo isn’t perfect but it can still be made to work really well with the parts you already have.