Flowmaster 40 Series Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72step · 02-19-2003, 01:28 PM

I am planning on replacing my current cheap crappy turbo mufflers with some 40 series flows. I know this is a dumb question, but my current mufflers are between the trailing arm and drive shaft with only a few inches to spare between there, and I'm just wondering if anyone else has flowmasters there and if there's any problem with clearance issues or if the flows are wider. The reason I want to ask before I order, is because the muffler shop I called suggested maybe I might need round mufflers because of the trailing arms when I told him it was a 72. I just want to make sure they will fit in there. Thanks in advance.

neonlarry · 02-19-2003, 01:59 PM

I have some and they just barely fit, but they do work fine. If you want, I can take a picture this afternoon and e-mail it to you. Are you sure you want flowmasters? I don't think they flow that well, and I am going to be replacing mine with a set of hooker mufflers.

Riles72 · 02-19-2003, 01:59 PM

Mine are mounted sideways. I know the picture is really dark, and hard to see, but there are no clearance problems and my truck is lowered 4 inches in the rear. I love mine...

Riley

Myride67c10 · 02-19-2003, 02:00 PM

I’m currently running 40’s with 2” pipes on mine and had no problems mounting them I see If I can get a picture and post it.

Myride67c10 · 02-19-2003, 02:09 PM

Here you go not the best pick but hope it can help.

jays68yak · 02-19-2003, 02:26 PM

I was thinking why not just put the mufflers before the trailing arm cross member. but I guess that would be an issue if you have a shorter wheel base truck. I think my suburban should have enough room to have them in front. Do you guys see a problem with that?

vfrdude · 02-19-2003, 02:46 PM

Mine are also mounted like Riles72 - I also have a 4 inch drop - no clearance problems...

ChevLoRay · 02-19-2003, 03:53 PM

Since my plan was to lower my truck, AND since it hadn't been done at the time, I ran my mufflers under the cab, between the frame rails and the rocker panels. I know this doesn't help, but it is what I did.

I'd like to run tail pipes to the rear, and I guess it will happen sometime in the future.

*Piston* · 02-19-2003, 04:24 PM

I did mine exactly like Myride67c10. 2.5" pipe with flowmaster 40's.

72step · 02-19-2003, 04:41 PM

Well, it looks like I'm screwed, I never realized the flows were so damn wide. Mine are between the driveshaft and trailing arm with a 4" drop too, and there is about 2" clearance on both sides of the muffler. I was trying to avoid paying for more labor, I might as well do the whole exhaust if I'm going to pay for them to re bend most of the pipes. I will take a measurement tonight on the width of my mufflers, and compare that to what the flowmaster specs of 10" wide, and take it from there before I make any decisions. Thanks, I will keep you posted to my findings...

Frank_Zeller · 02-19-2003, 05:13 PM

I had mine like Myride67c10 but they where vertical. Get the center in center out flow-masters.

68CST327 · 02-19-2003, 05:14 PM

Is there any problem with running Flowmaster 40's under a wood bed? I've heard those things make some massive heat, and that doesn't sound good for a wooden bed. Are there heat shields for these things?

Myride67c10 · 02-19-2003, 05:29 PM

I've never tried to see how much heat they put off, but I imagine they wouldn't be much hotter than the pipes themselves. Besides the majority of the time you are moving so I would think airflow would take care of most of the heat, an I don’t think that it would collect enough heat to cause damage while you are at an idle.

crazy longhorn · 02-19-2003, 05:39 PM

Those Flowmasters get HOT.....if you run them under a wood bed, I would watch the clearance, & use sheilds.....crazyL

Hotrod70C10 · 02-19-2003, 06:05 PM

Jays68yak, I have my crappy turbo's right at the back of the cab. They are turned down right before the trailing arm krossmember. I am planning going ahead and bolting a set of 40 series flows in the the place of the turbo's.

72step · 02-19-2003, 07:49 PM

Does anyone know if and how much wider the 40 series are than the crappy turbos?

Stano · 02-20-2003, 12:08 AM

I have three scars on my left arm to prove how hot they get! Within two miles and were hot enough to literally melt the skin on my arm looked like chewing gum when I jerked back. I would definately use heat shields on a wood floor bed.

neonlarry · 02-20-2003, 12:55 AM

They get hot because they have so much restriction with the many baffles that they have. I have heard many stories about vehicles (including trucks with wood beds) catching on fire from them.

02-19-2003, 01:28 PM	#1
72step Registered User Join Date: Nov 2000 Location: chimayo, nm, usa Posts: 898	Flowmaster 40 Series Question I am planning on replacing my current cheap crappy turbo mufflers with some 40 series flows. I know this is a dumb question, but my current mufflers are between the trailing arm and drive shaft with only a few inches to spare between there, and I'm just wondering if anyone else has flowmasters there and if there's any problem with clearance issues or if the flows are wider. The reason I want to ask before I order, is because the muffler shop I called suggested maybe I might need round mufflers because of the trailing arms when I told him it was a 72. I just want to make sure they will fit in there. Thanks in advance.

02-19-2003, 01:59 PM	#2
neonlarry Registered User Join Date: Feb 2002 Location: Vacaville, CA Posts: 2,746	I have some and they just barely fit, but they do work fine. If you want, I can take a picture this afternoon and e-mail it to you. Are you sure you want flowmasters? I don't think they flow that well, and I am going to be replacing mine with a set of hooker mufflers. __________________ 70 C/10 Light Red 350/TH350, HEI, Duals w/40 series Flows, 91 seat, LED taillights 99 Pontiac S/C GTP, SLP Ram Air hood, GMPP Konis & springs 95 Neon ACR, MP PCM, AFX UDP, 3.0 CAI

02-19-2003, 01:59 PM	#3
Riles72 Registered User Join Date: Feb 2000 Location: Chickasha, Oklahoma Posts: 117	Mine are mounted sideways. I know the picture is really dark, and hard to see, but there are no clearance problems and my truck is lowered 4 inches in the rear. I love mine... Riley Attached Images __________________ 72 Chevy short stepside 350/350 tilt, vintage air a/c sunset Orange Metallic paint Early Classic 2.5/4 drop eagle series 211 wheels

02-19-2003, 02:00 PM	#4
Myride67c10 Registered User Join Date: Oct 2002 Location: Asheville, NC Posts: 165	I’m currently running 40’s with 2” pipes on mine and had no problems mounting them I see If I can get a picture and post it. __________________ 1967 C-10 Use to be Riptide

02-19-2003, 02:09 PM	#5
Myride67c10 Registered User Join Date: Oct 2002 Location: Asheville, NC Posts: 165	Here you go not the best pick but hope it can help. Attached Images __________________ 1967 C-10 Use to be Riptide

02-19-2003, 02:26 PM	#6
jays68yak Registered User Join Date: Oct 2002 Location: Gilroy, CA Posts: 1,454	I was thinking why not just put the mufflers before the trailing arm cross member. but I guess that would be an issue if you have a shorter wheel base truck. I think my suburban should have enough room to have them in front. Do you guys see a problem with that? __________________ 1969 Chevy Project SWB Fleet, 20s, 5.3, t56, in the weeds. 1970 Chevy Truck cab on a 1979 Jimmy frame-8.1 liter 496 bbc/sm465/np203-jeds doubler-np205/d60/14bff Welded/42 tsls on recentered H1s 1998 Chevy Crew Cab K3500 SAS'd with hpd60, links and swayaway coilovers. 8.1l vortec DD/towrig "I like long walks, especially when they are taken by people who annoy me. "

02-19-2003, 02:46 PM	#7
vfrdude Registered User Join Date: May 2002 Location: Oakley, Ca. USA Posts: 137	Mine are also mounted like Riles72 - I also have a 4 inch drop - no clearance problems... __________________ Rudy Fierros '95 Honda VFR750F Used to have a '71 Chevy Stepside, Guards Red, Lowered 4" rear, 3" front, White Oak bed wood, 700R4 w/373 gears until some low life stole it!

02-19-2003, 03:53 PM	#8
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Since my plan was to lower my truck, AND since it hadn't been done at the time, I ran my mufflers under the cab, between the frame rails and the rocker panels. I know this doesn't help, but it is what I did. I'd like to run tail pipes to the rear, and I guess it will happen sometime in the future. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

02-19-2003, 04:24 PM	#9
Piston Account Suspended Join Date: Oct 2002 Location: Olathe, KS Posts: 2,301	I did mine exactly like Myride67c10. 2.5" pipe with flowmaster 40's.

02-19-2003, 04:41 PM	#10
72step Registered User Join Date: Nov 2000 Location: chimayo, nm, usa Posts: 898	Well, it looks like I'm screwed, I never realized the flows were so damn wide. Mine are between the driveshaft and trailing arm with a 4" drop too, and there is about 2" clearance on both sides of the muffler. I was trying to avoid paying for more labor, I might as well do the whole exhaust if I'm going to pay for them to re bend most of the pipes. I will take a measurement tonight on the width of my mufflers, and compare that to what the flowmaster specs of 10" wide, and take it from there before I make any decisions. Thanks, I will keep you posted to my findings...

02-19-2003, 05:13 PM	#11
Frank_Zeller Registered User Join Date: Jun 2001 Location: Austin, Texas Posts: 796	I had mine like Myride67c10 but they where vertical. Get the center in center out flow-masters. __________________ 69 SWB C/10 5-6 drop 700R4 69 Firebird Convert 455 4 spd 70 Torino GT Convert Austin-Texas

02-19-2003, 05:14 PM	#12
68CST327 Registered User Join Date: Aug 2002 Location: USA Posts: 443	Is there any problem with running Flowmaster 40's under a wood bed? I've heard those things make some massive heat, and that doesn't sound good for a wooden bed. Are there heat shields for these things?

02-19-2003, 05:29 PM	#13
Myride67c10 Registered User Join Date: Oct 2002 Location: Asheville, NC Posts: 165	I've never tried to see how much heat they put off, but I imagine they wouldn't be much hotter than the pipes themselves. Besides the majority of the time you are moving so I would think airflow would take care of most of the heat, an I don’t think that it would collect enough heat to cause damage while you are at an idle. __________________ 1967 C-10 Use to be Riptide

02-19-2003, 05:39 PM	#14
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	Those Flowmasters get HOT.....if you run them under a wood bed, I would watch the clearance, & use sheilds.....crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

02-19-2003, 06:05 PM	#15
Hotrod70C10 Low & Slow Join Date: Dec 2002 Location: Oklahoma Posts: 1,047	Jays68yak, I have my crappy turbo's right at the back of the cab. They are turned down right before the trailing arm krossmember. I am planning going ahead and bolting a set of 40 series flows in the the place of the turbo's. __________________ 70' C-10 LWB Fleetside 4.5/6 drop



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02-19-2003, 07:49 PM	#16
72step Registered User Join Date: Nov 2000 Location: chimayo, nm, usa Posts: 898	Does anyone know if and how much wider the 40 series are than the crappy turbos?

02-20-2003, 12:08 AM	#17
Stano Registered User Join Date: Jul 2000 Location: Mo Posts: 963	I have three scars on my left arm to prove how hot they get! Within two miles and were hot enough to literally melt the skin on my arm looked like chewing gum when I jerked back. I would definately use heat shields on a wood floor bed. __________________ New daily driver 96 Chevy K3500 crew cab dually 53,000 miles 350 Vortec 4L80 Nice ride 67 Chevy C-10 LWB Built 350 TH-400 Wifes ride and family rig: 2001 Furd Expedition 5.4 Liter Kickin back in Rolla,Mo. USA "Do the thing you fear most and the death of fear is certain" Mark Twain

02-20-2003, 12:55 AM	#18
neonlarry Registered User Join Date: Feb 2002 Location: Vacaville, CA Posts: 2,746	They get hot because they have so much restriction with the many baffles that they have. I have heard many stories about vehicles (including trucks with wood beds) catching on fire from them. __________________ 70 C/10 Light Red 350/TH350, HEI, Duals w/40 series Flows, 91 seat, LED taillights 99 Pontiac S/C GTP, SLP Ram Air hood, GMPP Konis & springs 95 Neon ACR, MP PCM, AFX UDP, 3.0 CAI

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