Welp!,... jetted right, a filter n' muffler is good for 2 to 4 horsies...
One muffler won't make much difference over another, due to the pipe diameter, exhaust manifold torque hump, and the valve size... but any aftermarket muffler will free up a little breathing over the stock one. Same for the filter,... it can't breath in any harder than it can breath out...
...but it's a 10% increase... Good enough for a real "seat of the pants" difference...
... and my best advice for jetting is,... more is not better, unless it
is better...
In other words,... don't just go for the bigger jet because you think it will mean more power,... you can end up with a loud, smoky, burping, farting, pig...
Bigger jets don't make more power... the correct jets do...
In Mikuni jets,.. I'd guess you are in 150 to 152.5 / 50 to 52.5 range... with 1/2 to 2/3 spacer... (totally guessing ) (don't know dynojets)...
Make changes, evaluate the results, and make your next move based on those...
... and have fun testing it out, and learning...
...
PS... sorry about the "unexpert" advice,... I only answered 'cause nobody else did...BUMP!
I don't know why people go the "dynojet" route at all. Some reason I don't know, and probably should. Maybe some other dynojetters will have more specific advice, or can straighten my a$$ out over why we should all have dynojets....
... no offense...