Originally Posted by fortyfied
I'm running the shorter stacks on my 347 and experiencing no problems at the top end or bottom.
You wont experience 'problems' just that you'll make (relatively) more power at the top with short and more power at the bottom with long. I couldn't start to estimate how much but it's very real. This is why many manufacturers have played with variable length stacks to get the best of all worlds.
Some bikes even run different length stacks front to back or side to side to 'spread' the power. Looks a bit odd when you can see all of them though as in the GT40!