# Exhaust replacement decision...2.5" or 3"?



## sdaly67 (Oct 21, 2013)

I want to upgrade exhaust after having engine redone on my '67. Engine 467 stroker high HP and Torque. I have a 2.5" exhaust but want to improve to better quality. so many options and opinions its confusing:


> X pipe or H pipe or neither?
> Aluminized or SS?
> 2.5" with reducers from 3" at headers or 3" system all the way out
> 
> I desire to optimize performance and still have moderate interior/exterior sound. What is the most desired approach all factors considered?


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## Old Man Taylor (May 9, 2011)

I would use a 3" system all the way. It's what I did on my '64 GTO. However, the 2.5" tail pipe would be fine. The challenge is picking a good 3" muffler that is a true 3" all the way thru. I used a Dynomax SS Super Turbo (#17774) muffler, but it is no longer available. 

What did you end up doing?


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## HiVolts (Jan 27, 2020)

I have 461 stroker. 2 inch Dougs Headers with true 3 inch Magnaflow MPE-15898 with X pipe. Love it.


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## EdGorman (Mar 26, 2020)

HiVolts said:


> I have 461 stroker. 2 inch Dougs Headers with true 3 inch Magnaflow MPE-15898 with X pipe. Love it.


What car?


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## Old Man Taylor (May 9, 2011)

It must be a Firebird since it has 2" Doug's headers.


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## EdGorman (Mar 26, 2020)

I maent you car that you put that system on. Wasn't sure if it was the one in your pic


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## HiVolts (Jan 27, 2020)

EdGorman said:


> What car?



70 GTO


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## EdGorman (Mar 26, 2020)

HiVolts said:


> 70 GTO
> 
> View attachment 134571
> View attachment 134572


Very nice. I built mt 463 with Butler products also, but hoping my modified tripower runs it My butler valve covers are going back for engraving


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## Old Man Taylor (May 9, 2011)

Mine's on my 64 GTO streetcar. I have a 4" system on my racecar.


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## EdGorman (Mar 26, 2020)

Old Man Taylor said:


> Mine's on my 64 GTO streetcar. I have a 4" system on my racecar.


Nice. So the Magnaflow worked out nice for you. I want the tailpipes to come straight out the back like the original 67 system


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## Old Man Taylor (May 9, 2011)

I don't have Magnaflow's on the streetcar, I have Dynomax Super Turbo's. Their combination of flow and noise control are hard to beat. On the racecar I have Racemaster's made by Flowmaster.


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## EdGorman (Mar 26, 2020)

Old Man Taylor said:


> I don't have Magnaflow's on the streetcar, I have Dynomax Super Turbo's. Their combination of flow and noise control are hard to beat. On the racecar I have Racemaster's made by Flowmaster.


Good info. I will have to look into them. Thank you. Got a pic of that GTO?


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## Old Man Taylor (May 9, 2011)

Pictures of the exhaust looking both directions, and a couple of the car. It's highly modified.


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## Old Man Taylor (May 9, 2011)

Some shots of the engine and the engine compartment.


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## EdGorman (Mar 26, 2020)

Very Nice! I'm trying to find a paint booth to rent, so I can shoot my Goat


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## Old Man Taylor (May 9, 2011)

I can't do that sort of stuff, so I have to save my money and pay someone. Here's a shot I like coming out of the paint booth 4-5 years ago. It reminded me of a GTO commercial.


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## Old Man Taylor (May 9, 2011)

HiVolts said:


> I have 461 stroker. 2 inch Dougs Headers with true 3 inch Magnaflow MPE-15898 with X pipe. Love it.


Do you have a part number for the 2" headers? I was only aware of the 1 7/8" Doug's headers for round port heads.


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## HiVolts (Jan 27, 2020)

Taylor,
Went through receipts. You’re right. Looks like 2’’ were planned but receipt shows part # D567 1 7/8. I purchased car already built. Thanks


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