RE: GrPro engine support
We already knew what the deal was and was going to be. That's why Mistydee0 ended his association with GR Pro. Misty was an importer/dealer and did not like the fact that he could not take care of his customers while selling a GR Pro product.
You can contact Mistydee0 at LS Pro engines where he now is the prime importer/distributor for the MT line of engines. Excellent support and a good product. About the best you can do with the engine you have is to chalk the GR engine you have up to experience and move forward.