Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.
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rr6pak
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by rr6pak » Sat Oct 22, 2016 2:14 am
I have 1 7/8" headers with 3" collectors on my '71 RR. Having a brain fart as to what is the machine gun tips are suppose to be for my car, long or short? What are your suggestions and anyone have pictures? Also, debating on if I should run 3" or 2.5" exhaust to the back and after market mufflers or resonators like factory.
Oh, decisions, decisions

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71bird
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by 71bird » Sat Oct 22, 2016 10:51 am
Road Runners had the short tips and Chargers longer ones. As far as mufflers and so forth, it all depends on what kind of sound you like. With my Hemi, I ran a 2 1/2 H pipe system all the way back with repo Hemi mufflers and resonators with tips. But for me I don't like going down the road and not being able to hear the stereo for the constant rumble. Accurate Exhaust can make a complete repo system in 2 1/2 and they have three different flow and sound levels for the Hemi muffler and they have which ever tip you want also.You could go with 3" to the mufflers, and then 2 1/2. Their stuff fits just like factory. Now the tips for resonators are completely different than standard tips.
71 Road Runner - J68
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moparite
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by moparite » Sat Oct 22, 2016 1:03 pm
Engine displacement and mods to it determine exhaust size. More info on that would be helpful.
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rr6pak
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by rr6pak » Sat Oct 22, 2016 1:24 pm
Yea, I'm leaning towards Accurate for my exhaust. Wish I can figure out how to re-size pictures for the tips I found

Just need to decide either 3" all the way or 2 1/2".
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rr6pak
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by rr6pak » Sat Oct 22, 2016 1:26 pm
moparite wrote:Engine displacement and mods to it determine exhaust size. More info on that would be helpful.
Ok. 400 stroked to 470, 585 hp/610 torque, Edelbrock heads, Doug's 1 7/8" ceramic headers with 3" collector

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dangina
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by dangina » Mon Oct 24, 2016 3:48 am
rr6pak wrote:moparite wrote:Engine displacement and mods to it determine exhaust size. More info on that would be helpful.
Ok. 400 stroked to 470, 585 hp/610 torque, Edelbrock heads, Doug's 1 7/8" ceramic headers with 3" collector

did you get it on the dyno>? which kit did you use? I have the same motor and I can only get 354hp/460 torque. I found out my brand new firecore distributor magnetic pickup came loose, would this cause this much of a hp lose or should I look elsewhere?
400 stroked to 470ci, 3:55 Eaton true trac, slightly upgraded suspension lol
BUILD THREAD!!!! http://www.protouringmopar.com/showthread.php?796-1971-Speedipus-Rex&highlight=speedipus
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rr6pak
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by rr6pak » Tue Oct 25, 2016 12:10 am
dangina wrote:rr6pak wrote:moparite wrote:Engine displacement and mods to it determine exhaust size. More info on that would be helpful.
Ok. 400 stroked to 470, 585 hp/610 torque, Edelbrock heads, Doug's 1 7/8" ceramic headers with 3" collector

did you get it on the dyno>? which kit did you use? I have the same motor and I can only get 354hp/460 torque. I found out my brand new firecore distributor magnetic pickup came loose, would this cause this much of a hp lose or should I look elsewhere?
Yes, it was put on the dyno. Many variables can be looked at for the low numbers you have but with the pickup being loose, seems like it is a good place to start
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mclean03
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by mclean03 » Mon Jan 30, 2017 5:56 am
Any update? Did you get 2.5" or 3", and how's the sound?
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rr6pak
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by rr6pak » Mon Jan 30, 2017 7:16 pm
mclean03 wrote:Any update? Did you get 2.5" or 3", and how's the sound?
Not for me, for now. It's a work in progress. Having to work and put out many fires..lol