I put a mini starter on my car and every now and then it will grind. I have shimmed it out and back in to no avail. Here is the question. I was told to splice in a ford solenoid and the starter problems will go away. Has anyone ever heard of this?

Installing a Ford solenoid is a good idea and will help with starter drag. The solenoid will stay cooler and help with heat soak. But it won't do a thing for starter grind. Shimming fixes that.

Is your flywheel missing any teeth?

no missing teeth, and i have shimmed it, it never got anybetter