Dick
What kind off muffler have you found to give the best all around performance?

If using a tuned pipe do gas engines get peaky, like the glow versions do? I ran a g-23 in my boat. i had a water cooled head, higher compresson, big bore carb and a tuned pipe. The engine really wasn't crisp untill mid range. From there on up it hauled butt.
I haven't tried a tuned pipe on my ZDZ-60's. I am running a bison pitt's style muffler. Would i get better performance by making a header pipe that has smoother bends. Then have the header go into a 1 1/2" diameter pipe about 7" long. then have 2- 5/8" tail pipes. How long should the header be before the muffler? Making it look like a bison muffler. Noise is not a concern.

As far as engine mods go, it seems preety hard to improve the ZDZ line right now so i am looking at the exhaust.