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Discussion Starter · #1 ·
:grrrrrr:Well I took my 1970 chevy truck to get new exhaust today it took all day. I had decided to use a local shop to perform the service and we had decided to run standard mufflers and run straight duel exhaust porting each side of the exhaust out the side in front of the wheel well. I made it about four miles down the road when the exhaust manifold broke......:grrrrrr: I am so mad i could puke. I drove it the rest of the way home with it being incredibly loud. i phoned the guy who did the work and he seems to think it was just a coincidence. i think he broke the damn thing bending and cutting the pipe (he used a saws-all) without disconnecting it from the manifold. it is at least 1/4 inch cast steel so i find it hard to believe that it was metal fatigue, at least without some help from the mechanic. what do you guys think?

So now i am looking at parts and labor on new manifold install and we have to hope he doesnt break the bolts in the manifold...
my question is this .. on the 350 V8 in the 1970 truck is there any special things to know about converting it from original exhaust to duel exhaust? the original set up has the left side of the engine exhaust coming off the manifold straight back and then the right side comes off the manifold and hits a 90 degree turn and meets the other pipe from the left and then flows into the muffler. The mechanic simply cut the 90 off and straightened the pipe and let the right side flow to a single muffler and out the right side of the truck, the left is straight to another muffler and out the left side. is it okay to have these mufflers seperate servicing only each side of the engine completely seperate? i ask this because i had that ram style manifold break on the right after the conversion and am just concerned that if i repait the manifold i may end up with further problems.
 

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To do the job properly, he should have removed all of the old pipe from the manifolds and installed new from there back. Did he use any hangers anywhere attaching the system to the bottom of the truck, if not, that could explain the cracked manifold.
 

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Everything the moderator said is true, should have started from the manifold and make sure it is supported. The manifold can be welded (if welded make sure the battery is disconnected or it can fry some wires or accessories) or you can switch to exhaust headers. In 1987 I installed headers and two separate exhausts on my '68 C10. The only effect was my exhaust got a little louder (something about the combined exhausts help cancel each other). If you have a stock engine the difference should be negligible.

Bob Humphreys
 

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Discussion Starter · #4 ·
thanks =)

Thanks for the replies! :glasses: I ended up buying a replacement manifold and he did the job charging me for 1 hour labor.

The hangers are very stiff , very little if any movement is allowed with the hangers he used, the rubber bushings he used are very stiff he drilled holes in the frame to hang them :no: not so sure if welding a hanger wouldnt have been best , i dont like the idea of holes in my frame. but hey it is done now. the hangers allow very little movement of the mufllers and exhaust in general. I had suspected the hangers as being an issue. Only time will tell if they will cause further damage possibly to the new manifold or the other side.
 

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Keep an eye on it, some play is necessary due to the engine moving on it's mounts as you accelerate and decelerate.
 
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