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Old 11-08-2009, 05:07 PM   #1
Hoffman65burb
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454 Exhaust

Hey,

I have a 454 bbc in my 78 jimmy. It has a quadra jet 4 barrel, long tube headesr, RV cam,HEI, and duel glass packs. The exhaust is only 2 1/4, is that too small for this motor? Im looking to swap the glass packs out(preferr the deep tone of a flowmaster than that blaat). If im going with 1 chamber flowmasters, would that cause too much back pressure?

thanks
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Old 11-08-2009, 07:58 PM   #2
PhilaTruck
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Re: 454 Exhaust

Should be no problem at all with the RV cam.
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Old 11-08-2009, 08:54 PM   #3
shilo
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Re: 454 Exhaust

1 chamber flowmasters are really loud. Mainly for race cars that require a "muffler", 2 chamber would sound nice and good
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Old 11-08-2009, 09:03 PM   #4
Scootin 81 C20
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Re: 454 Exhaust

I can only imagine how that 454 sounds with the same setup as my 350. It cracks with mine, it must sound mean on yours.
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Old 11-08-2009, 09:54 PM   #5
Hoffman65burb
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Re: 454 Exhaust

ok thanks for the info. The 40 series is a 1 chamber right? i liek the loud, i just like the deep tone of the flowmaster rather than the glass pack
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Old 11-09-2009, 01:44 AM   #6
shilo
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Re: 454 Exhaust

40 series is the 2 chamber
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Old 11-09-2009, 05:08 PM   #7
BossHogg69
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Re: 454 Exhaust

2.25 is good for about 350hp or so. I had almost the same setup on the 454 in my '69 (it is a '79 model engine) except I was running manifolds and 2.5" pipes with flowtech afterburner mufflers. 2 chamber FM's will sound good on that 468.
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