I have an MVVS .77 and want to use a standard or regular muffler. The #3255 muffler from MVVS is supposed to be for the .61, .77 and .91 but it sure looks small for such large displacement engines. How well will it work for the .77? I have a muffler for an O.S. Max .61SF that is much larger in volume and fits the bolt pattern. What do you think?