Installing truck stacks

[Dak44312]

Necessary to fill the exhaust tip bolt holes? I can hear them leaking with the stacks off, just wondering if the stacks fit so tight that it won't matter?

[Jess from VA]

I had to rap mine on with a 2 X 4 (over the tip ends) with a rubber mallet.  Pretty tight fit, even after cleaning up all the carbon/crud.

I drilled all three (existing) holes in my new (Air Flow) tips to reuse the bolts and holes.

After the job was finished, I figured those tips would stay on just fine with one bolt (each) (the inside one, so it doesn't show).

I would not use no bolts because a few bad bumps (or something) could cause one to depart the bike.

If you don't use all three bolts, I think the tips are so snug, you will not hear any gas escaping the unused muffler holes.  Course I don't know what tips you are using.

[Dak44312]

I know they are a tight fit, so I was planning on NOT using any hardware. I am using the 36" stacks with Grumpys tips.

[Jess from VA]

Well, I was describing just replacing my std 18" tips, not full length stacks.  I have no experience with those.  It seems to me using less hardware/fasteners (with a super snug fit) would be OK, but having at least one fastener somewhere would be a good safe idea.

Besides hard bumps, there could be an issue with big temperature changes, like taking the bike out on a cold day, then firing it up hot (with resultant expansion).

I still don't think it necessary to fill the muffler holes.... and I try to leave things alone where it is possible you or someone else may want to go back to original parts sometime down the road..