Exhaust is installed

[Yukon Jack]

Drove the K20 to American Muffler and had exhaust installed. The system is 3" pipe from the headers to the x-pipe, then 2 1/2" to Dynomax UltraFlo's and continues as 2 1/2" pipe dumping at the rear of the flatbed angled down slightly. The truck is running pretty rough, back firing or missing - now that I can actually hear the motor it sounds like a timing issue and a rocker or two need to be adjusted.

Here are some pics of the system. This is the X-pipe that I had built by someone I found on E-bay.



Rather than use the collector piece that came with the headers, American Muffler made their own piece



The passenger side collector was fairly close to the transfer case. Here is a pic of the pipe coming over the transfer case





Here is the X-pipe installed directly behind the transfer case







And here is an example of the welds at the X-pipe



Here are the Dynomax mufflers



Pretty straight shot to the rear of the truck



The pipes dumb right before the hitch and are well protected



As the motor is running rough I have not gotten on the gas to see how the system sounds - will have to wait to see what is wrong with the motor.

[LUV2XCLR8]

[86SILVERADO]

Yukon,

Looks good, must feel good to be finally seeing the light with your rig. Just curious what is the reason for the x pipe I see some other guys with it as well. Keep us updated on the misfire thing. Mine has been running rough lately to. Nothing to bad but a little misfire. Did the tuneup yesterday and no difference. Adjusted the valves in and out a half turn each way and no difference. Fully charged battery with no difference. Played w/timing 5 degrees or so either way, new fuel and air filters, re-adjusted carb, did compression check, dead on 150 on every cylinder. One side of my true dual exhaust has some holes before the muffler but the other side is brand new and it misfires out of that bank to so I am kinda stumped at this point. This problem really came on about the time when gas prices started to go up. I think they have been mixing a little #2 in there to bump up profit margins or something. Seriously though if you get it nailed down keep us posted. Good luck with it.

[70c10swb]

sweet! hows it sound

[Yukon Jack]

The X-pipe is supposed to even out the exhaust a bit, maybe tone it down a little too. Well, after driving home, it is LOUD . . . you will definitely know I'm heading your direction if you meet me on the road.

Definitely feels good to be getting towards the end of the project. I'm ready to enjoy and stop working on it for awhile.

[86SILVERADO]

I see,

Was wondering what they were all about. Man you could camp out under that thing. I though I had plenty of room under my one ton.

[68Stepbed]

The x-pipe equalizes the exhaust flow and also creates a scavenging affect pulling and forcing exhaust from cylinder that fire on the opposite bank. Read about it in HotRod magazine a while back. It helps a little in the horsepower dept. but creates a lot more torque.

The system looks great.

[1STtimePRo'71]

Looks really nice Yukon. I hardly see any hangers under there either.

[Yukon Jack]

Here is an audio file of the exhaust at idle

and reving

Just ignore the lifter noise, hope to get that fixed tonight

[72gord]

Looks good Yukon, that truck must really be lifted!!! The exhaust looks like it goes above the frame in that one shot, and that front driveshaft has quite an angle to it. I bet it feels good to drive it!!! We got ours out after one year of working in the garage on it, not even close to done, but felt good to drive it!!

[vtblazer]

I've got those same mufflers on my 70 blazer w/350 and their not exactly quiet, I bet their loud behind a big block.

Looks like a super clean install, something about exhaust done right.

[GreyHoundSteve]

That is a VERY NICE looking set up you have there. Good work, quality bends, nice job.

[Yukon Jack]

Thanks for the compliments. I am impressed with the job they did. The body lift really allows the exhaust to be tucked up high.

As for the engine, I have a separate post going - pulled the passenger side valve cover and three rockers were sitting sidewise. Also found a bent pushrod. Didn't pull the drivers side yet, I just went inside and went to bed when I found this problem.