So, after over 10 years of use, my mounting plates for my pro .15 (got that stupid thing running again , all of its problems were being caused by a bad fuel tank spring and exhaust header) are rather worn, one of the screw holes are stripped, etc. My question is, do I need the old mounting plates when I upgrade to a 3.3 engine? I just ordered #4400 but it hasn't arrived yet, and if I need the mounts I would like to get them as soon as possible.The 2 brackets shown in the picture are what I am talking about in this. Thanks a lot.