Just a few words of caution...
For the hole saw rookies:
Expect to get a hole LARGER than the hole saw is marked at.
How much larger depends on the condition of the hole saw (old and mangled = much larger hole)
Also...
Keep in mind the possible loads that these members will experience (use a healthy safety factor- depending on location, it could be very difficult to replace at Competition). Run some stress and strain calculations with the proposed reduced cross-sections before you start going completely crazy (2.75" hole in a 3" wide tube
) with the hole saw...
No one wants to have the piece that they spent hours swiss-cheesing break in half...
my two cents
-Bill