I have an old banana mufller I would like to put the two GT outlets into...
Where should I put the outlets, and what size should they be. I am putting in a small bore six

Hi Pete- I would think 2.5" pipes would be about right; do you want the traditional GT look or the newer GT style with the pipes close together?

GT 3 look is my vote 2.5” is what these areClick to view attachment

Ben
I want to piggy back on this question….he said small bore six. Does the 2.5 still hold…..as headers vary based on bore.
I was under impression too large a pipe may not provide sufficient back pressure.
May not change your answer …..but just want to confirm.
Thanks

@mb911 - That muffler looks awesome and I bet it sounds good too.

I think the original GT spacing would be preferred. Although close together looks great as well!

old article how to...

Neat modification
I assume this can be done similarly to the 4 Cyl Banana muffler for those of us who can afford a muffler mod but not a 6 yet?
Backpressure probably an issue....

I also planned this mod some time ago and haven’t gotten to it yet.. I was thinking that if the sound level is greater than desired, I should be able to add aftermarket sound baffle inserts (like are used with motorcycle exhausts to quiet them) into the two exit pipes. Perhaps that would add back pressure too, if found to be beneficial. Just a thought.

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^^ there is nothing quiet about a sport muffler and with the car I was in, it got really loud between 3,000-3,500 RPM.

I run a tail pipe blocked off to keep it tame and works well for my 2.4 with 993 heat exchangers

Regarding high decibels.. since the body has to be cut open to make changes anyway - is there a modern muffler packing product that could be added before closing it up? Why is steel wool coming to mind
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