Through frame solid mounted exhaust ques. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

polevault1977 · 09-27-2003, 12:07 PM

I'm planning on running my exhasut through the frame. I have machined 4 brackets that will hold the 2.5 inch tubing solidly at the point it goes through the frame. I think Copperhead is fabbed like this. I realize that I will have to run flexible hose, stainless braided behind the headers to allow the engine to torque. My question is, has anyone try this set-up. I am concerned with vibration transferred to the cab and if this set up has any other draw backs. Your thoughts, pro or con, would be apprecaited. BTW, I haven't ruled out using regular exhaust hangers and not going with the solid mounts. Cheaper anyway! I'll attach a pic of the bracket I'm talking about. It's split in the middle, probably won't show up on the pic. Thanks, Danny

jamis · 09-27-2003, 05:25 PM

I was thinking of the same thing. But I dont recommend flex exhaust pipe even the the best stainless brands dont last long. I was thinking of just making a 4" hole and welding in some gussets to reinforce the trailering arm crossmember and run the pipe threw the center.The only draw back I see, is there will be two 90 deg bends to go up and over the trailering arms like project copperhead. Then you need another two 90 deg bends again to go under the rear mounted tank. Just too may bends.

I want to run a big block and the more I think about it , over the frame headers sound like a better way to go.

Hutch · 09-27-2003, 06:12 PM

polevault1977
What happens to the Emergency-brake cable system?
Texas requires an E- brake to pass yearly saftey inspection.

polevault1977 · 09-27-2003, 06:54 PM

I did put new e-cables at the drums but I will probably not hook them up. Here in OK, they dropped our state inspection, so that won't be a prob. I still think I could hook up them up if I wanted. They would have to routed closer to the frame since I have welded in a 4 inch sleeve in the trailing arm crossmember where the old cable went through.

I agree on the too many 90 deg bends. I ordered a shorter gas tank 16 front to back. This gives me about 6.5 inches to make the bend going through the panhard crossmember. It will be closer to a 70 degree bend and I think I can live with that.

I just am still kicking around the solid mount vs. tradional hangers. Still taking suggestions!!! Danny

jamis · 09-27-2003, 07:13 PM

That looks good to me, I think the hole is big enough that the exhaust will go right threw it and not have a problem hitting. Your going to have new motor and transmission mounts so engine movement shouldnt be a problem.

What drop are you using?

E-brake test is easy to pass....just put a kill switch on your brake lights...so they cant tell your on your foot brake. he he he he.....also good for ditching the cop at night

polevault1977 · 09-27-2003, 11:41 PM

jamis, i am running a 3.5/6 from early classic ent. That is 2.5 drop spindles w/ 1 inch drop spring in front and 6 inch drop spring in the rear. The above pic is an old one. i have a 350/700 set-up installed now. Danny

I finally got a 100 post, so I get a avatar now, right!!

Longhorn Man · 09-27-2003, 11:45 PM

Engine movement will be a problem onless you go with solid motor mounts.
Ask GMC junkie...she just went through this.
i would go with normal mounts.

09-27-2003, 12:07 PM	#1
polevault1977 Pick'n up the pieces! Join Date: Sep 2002 Location: Marietta, Oklahoma Posts: 198	Through frame solid mounted exhaust ques. I'm planning on running my exhasut through the frame. I have machined 4 brackets that will hold the 2.5 inch tubing solidly at the point it goes through the frame. I think Copperhead is fabbed like this. I realize that I will have to run flexible hose, stainless braided behind the headers to allow the engine to torque. My question is, has anyone try this set-up. I am concerned with vibration transferred to the cab and if this set up has any other draw backs. Your thoughts, pro or con, would be apprecaited. BTW, I haven't ruled out using regular exhaust hangers and not going with the solid mounts. Cheaper anyway! I'll attach a pic of the bracket I'm talking about. It's split in the middle, probably won't show up on the pic. Thanks, Danny Attached Images

09-27-2003, 06:12 PM	#3
Hutch Registered User Join Date: Oct 2001 Location: Grapevine, Tx. Posts: 2,142	polevault1977 What happens to the Emergency-brake cable system? Texas requires an E- brake to pass yearly saftey inspection. __________________ John Hutchison Grapevine,Texas 68 1/2 t swb 68 Mustang 69 Jaguar 71 1/2 t swb 88 Supra CompTs6m 93 Escort GT 2005 Corolla XRS

09-27-2003, 06:54 PM	#4
polevault1977 Pick'n up the pieces! Join Date: Sep 2002 Location: Marietta, Oklahoma Posts: 198	I did put new e-cables at the drums but I will probably not hook them up. Here in OK, they dropped our state inspection, so that won't be a prob. I still think I could hook up them up if I wanted. They would have to routed closer to the frame since I have welded in a 4 inch sleeve in the trailing arm crossmember where the old cable went through. I agree on the too many 90 deg bends. I ordered a shorter gas tank 16 front to back. This gives me about 6.5 inches to make the bend going through the panhard crossmember. It will be closer to a 70 degree bend and I think I can live with that. I just am still kicking around the solid mount vs. tradional hangers. Still taking suggestions!!! Danny Attached Images

09-27-2003, 07:13 PM	#5
jamis F.A.S.T. president Join Date: Sep 2003 Location: Florida Posts: 1,883	That looks good to me, I think the hole is big enough that the exhaust will go right threw it and not have a problem hitting. Your going to have new motor and transmission mounts so engine movement shouldnt be a problem. What drop are you using? E-brake test is easy to pass....just put a kill switch on your brake lights...so they cant tell your on your foot brake. he he he he.....also good for ditching the cop at night Last edited by jamis; 09-27-2003 at 07:17 PM.

09-27-2003, 05:25 PM	#2
jamis F.A.S.T. president Join Date: Sep 2003 Location: Florida Posts: 1,883	I was thinking of the same thing. But I dont recommend flex exhaust pipe even the the best stainless brands dont last long. I was thinking of just making a 4" hole and welding in some gussets to reinforce the trailering arm crossmember and run the pipe threw the center.The only draw back I see, is there will be two 90 deg bends to go up and over the trailering arms like project copperhead. Then you need another two 90 deg bends again to go under the rear mounted tank. Just too may bends. I want to run a big block and the more I think about it , over the frame headers sound like a better way to go.

09-27-2003, 11:41 PM	#6
polevault1977 Pick'n up the pieces! Join Date: Sep 2002 Location: Marietta, Oklahoma Posts: 198	jamis, i am running a 3.5/6 from early classic ent. That is 2.5 drop spindles w/ 1 inch drop spring in front and 6 inch drop spring in the rear. The above pic is an old one. i have a 350/700 set-up installed now. Danny I finally got a 100 post, so I get a avatar now, right!!

09-27-2003, 11:45 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Engine movement will be a problem onless you go with solid motor mounts. Ask GMC junkie...she just went through this. i would go with normal mounts.



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