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Old 09-26-2010, 05:53 PM   #1
turner72
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Need Help

Not sure if this is a problem or not. I have a 71 350/350 with the LMC dual exhaust with glasspack style mufflers. When you let off the gas at speed I get kind of a blatty backfire sound from the exhaust. Other than that the engine runs great. Is this normal with the glasspacks?
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Old 09-26-2010, 06:14 PM   #2
Lee H
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Re: Need Help

Could just be the sound of your glass packs. A backfire in the exhaust on deceleration is usually do to a leak. Recheck all your connections.
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1972 C10 SWB, Air, PS, PB, 350/350THM. Second owner.

1965 Corvette roadster, 44K miles, 327/365 SHP, 4 speed, side exhaust, knockoffs, teak, second owner (bought in 1970), Have ALL numbers matching components.

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Old 09-26-2010, 08:06 PM   #3
JimKshortstep4x4
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Re: Need Help

If you used the light duty clamps that are furnished with the set then that may be your problem. The pipes have fairly heavy walls and heavy duty clamps are need to clamp the pipes together.

Jim
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1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end
1965 Impala SS 400 sbc, Muncie rock crusher
1966 Impala SS 396 bbc, TH 400
1969 El Camino, 350 sbc, TH 350
1971 Snowplow built on a Blazer frame
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Old 09-26-2010, 09:00 PM   #4
swamp rat
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Re: Need Help

I'm not a fan of muffler clamps, welding is the way to go, recheck your manafold gaskets too.
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