This is a subject that has always blown my mind, exhaust. I have a 59 235 and I would like it to sound like a deep lowrider or cruiser. I do not want to hear only the exhaust as I ride down the road. So the next thing is straight exhaust. I don't believe a straight through muffler (dynomax)would bother the engine, but does the older engines require any backpreasure. I don't want to lose power for a gain of speed. Any suggestions?