Running exhaust OUTSIDE of the frame? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

PrimeredThunder · 08-04-2004, 06:07 PM

Is it possible to run the exhaust outside of the frame on a 67-72 Chevy truck? I would be running Ramshorn Manifolds and using Flowmaster mufflers. The mufflers would be mounted underneath the doors and have turndowns.

Yes, I know it will be loud, especialy in the cab, but I need to do it for ground clearance if I go through with lowering my truck even more this winter. Any pictures or suggestions would be great.

Thanks,

Kenny

Tx Firefighter · 08-04-2004, 06:10 PM

Lots of guys have run them outside the frame. Usually, you can see where the bottom corner of the cab is bent for the pipes to run through. Usually, you can bend them back later if you want.

LUV2XCLR8 · 08-04-2004, 06:32 PM

My Old 70 With The 250 In It Had A 3" Flow Under The Drivers Side
With A Turn Down, I Loved It, Until I Hit Something & Tore It Off.

Longhorn Man · 08-04-2004, 07:55 PM

Wouldn't the floor be higher on the inside of the frame rail than on the outside? (Where the floor slopes down to the door opening) Any good pipe shop should be able to run a set of pipes back to the bed and stay inside the frame rails. The only mod you'd have to do is chop a hole in the cross member for the pipe(s). I've seen quite a few with the X-member cut (the one where the C-bearing is if so equipped) and one of them was a 12 second street driven daily driver.

XXL · 08-04-2004, 08:11 PM

Quote:

Originally Posted by PrimeredThunder

Is it possible to run the exhaust outside of the frame on a 67-72 Chevy truck? I would be running Ramshorn Manifolds and using Flowmaster mufflers. The mufflers would be mounted underneath the doors and have turndowns.

I ran mine like this. The turnout from the engine happens just forward of the firewall where the frame curves up. Once it's outside the frame rail it's all done. Muffler behind the rocker panel and then between the cab rear and mount to get under the bed. As TX mentioned, you do have to notch/bend the inner edge of the rear of the cab to get a little clearance. Rinse. Repeat.

67cst · 08-04-2004, 08:22 PM

mine are inside the frame rails and tucked waaaaay up, i think its a great setup, the pipes run though the crossmemeber described in the post above

68C15 · 08-04-2004, 09:23 PM

I see where he is coming from on this question. with the trailing arm style rears there is very little room for exhaust. factor in the lowered suspension & you are just about of options.
I am going with a big block which will need 3" pipes & headers. I plan on using the 4" round magnaflows & would also like them outside the frame for rear suspension clearance. can a guy go through the frame sides under the cab safely? maybe box that area for strength? then run them along frame with mufflers under the bed?
just brainstorming, thanks.

PrimeredThunder · 08-05-2004, 03:23 AM

Thanks for the help and suggestions...

I considered running it back above the frame and thr0ough the Trailing-Arm Crossmember with holes, but I plan on doing some surgery on the back of my frame and I need all the room I can get.

If anyone has a setup like I mentioned PLEASE post pictures!

Kenny

08-04-2004, 06:07 PM	#1
PrimeredThunder Back from the Dead Join Date: Dec 2001 Location: Salem, Oregon Posts: 522	Running exhaust OUTSIDE of the frame? Is it possible to run the exhaust outside of the frame on a 67-72 Chevy truck? I would be running Ramshorn Manifolds and using Flowmaster mufflers. The mufflers would be mounted underneath the doors and have turndowns. Yes, I know it will be loud, especialy in the cab, but I need to do it for ground clearance if I go through with lowering my truck even more this winter. Any pictures or suggestions would be great. Thanks, Kenny __________________ The only Carb that matters to me is the one under my hood! Salem, Oregon

08-04-2004, 06:10 PM	#2
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Lots of guys have run them outside the frame. Usually, you can see where the bottom corner of the cab is bent for the pipes to run through. Usually, you can bend them back later if you want. __________________ I'm on the Instagram- @Gearhead_Kevin

08-04-2004, 06:32 PM	#3
LUV2XCLR8 The LuvShack Garage Join Date: Jan 2004 Location: Maple Grove, TN (West Side) Posts: 30,484	My Old 70 With The 250 In It Had A 3" Flow Under The Drivers Side With A Turn Down, I Loved It, Until I Hit Something & Tore It Off. __________________ Owner/Op: "TN Classic Transport Carriers" The Toy: "Square Vette" 72 Hybrid Blazer Toy Barn: "LuvShack" 40 x 60 x 20 Shop Tow Piggy:"Maddy" 88 Silverado 3500 Hauler: "Feathers" 14 Aluma 8218T

08-04-2004, 08:22 PM	#6
67cst i love summertime Join Date: Jul 2002 Location: Kelowna BC Posts: 4,303	mine are inside the frame rails and tucked waaaaay up, i think its a great setup, the pipes run though the crossmemeber described in the post above Attached Images __________________ 1967 shortbox stepside Chevy, 365 hp 327, th400. GLOVE BOX LIGHTS FORSALE, click link for info http://67-72chevytrucks.com/vboard/s...d.php?t=273724

08-04-2004, 09:23 PM	#7
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	I see where he is coming from on this question. with the trailing arm style rears there is very little room for exhaust. factor in the lowered suspension & you are just about of options. I am going with a big block which will need 3" pipes & headers. I plan on using the 4" round magnaflows & would also like them outside the frame for rear suspension clearance. can a guy go through the frame sides under the cab safely? maybe box that area for strength? then run them along frame with mufflers under the bed? just brainstorming, thanks. __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card

08-04-2004, 07:55 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Wouldn't the floor be higher on the inside of the frame rail than on the outside? (Where the floor slopes down to the door opening) Any good pipe shop should be able to run a set of pipes back to the bed and stay inside the frame rails. The only mod you'd have to do is chop a hole in the cross member for the pipe(s). I've seen quite a few with the X-member cut (the one where the C-bearing is if so equipped) and one of them was a 12 second street driven daily driver.

08-05-2004, 03:23 AM	#8
PrimeredThunder Back from the Dead Join Date: Dec 2001 Location: Salem, Oregon Posts: 522	Thanks for the help and suggestions... I considered running it back above the frame and thr0ough the Trailing-Arm Crossmember with holes, but I plan on doing some surgery on the back of my frame and I need all the room I can get. If anyone has a setup like I mentioned PLEASE post pictures! Kenny __________________ The only Carb that matters to me is the one under my hood! Salem, Oregon



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