A question for those past this point. How much and which way did you have to trim the lower cowling opening for the exhaust pipe? It looks to me like the muffler and the four pipes from the cylinders are a tight fit with other parts and the cooling shroud. In order to move the muffler to the right to clear the cooling shroud on the left it seems that the hole in the lower cowl would have to be enlarged considerably. I'd like to know how earlier builders handled this before I start hacking out a bigger opening!