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Exhaust systems...


98Z
11-16-2013, 11:37 PM
Greetings everyone...

I own a 1998 Silverado Z71 5.7L/auto. After a little over 200K on the clock, she's getting a freshly rebuilt engine installed this week (camshaft issues and low end noise prompted the rebuild). This truck is breathing through stock air intake and stock exhaust. I plan to put on an open element intake setup and want to get the air out just as fast as in, so I'm looking for suggestions on what to do with the exhaust.

I know this topic is as arbitrary as what brand of oil to use, but I'd still like any opinions and advice that anyone has to offer. Links to suggested exhaust systems would be helpful as well.

It currently has the stock two into one muffler with a single outlet behind the passenger's tire. I want to move that into the split rear exit. Personally, I'd love to replace the stock manifolds with headers and just do a complete exhaust replacement, but I don't have that kind of money to spend, so the stock manifolds stay.

I fear the stock cats have seen their better days as I have an engine light that won't go away that always tells me that the cat is inefficient, or something along those lines. I can't get that damned light to stay off!

So, what do you think? I'd like a low growl, but not obnoxious. Not something I have to crank the stereo to drown it out or to actually hear the radio.

j cAT
11-17-2013, 07:29 AM
Greetings everyone...

I own a 1998 Silverado Z71 5.7L/auto. After a little over 200K on the clock, she's getting a freshly rebuilt engine installed this week (camshaft issues and low end noise prompted the rebuild). This truck is breathing through stock air intake and stock exhaust. I plan to put on an open element intake setup and want to get the air out just as fast as in, so I'm looking for suggestions on what to do with the exhaust.

I know this topic is as arbitrary as what brand of oil to use, but I'd still like any opinions and advice that anyone has to offer. Links to suggested exhaust systems would be helpful as well.It currently has the stock two into one muffler with a single outlet behind the passenger's tire. I want to move that into the split rear exit. Personally, I'd love to replace the stock manifolds with headers and just do a complete exhaust replacement, but I don't have that kind of money to spend, so the stock manifolds stay.

I fear the stock cats have seen their better days as I have an engine light that won't go away that always tells me that the cat is inefficient, or something along those lines. I can't get that damned light to stay off!

So, what do you think? I'd like a low growl, but not obnoxious. Not something I have to crank the stereo to drown it out or to actually hear the radio.

since you live in an area of cold weather you are going to use this truck in cold and snow. the OEM intake air filter system is best along with the throttle body being heated by the coolant.

on the cat converters the OEM converters are the best for proper operation and low restrictions. the issues with the dtc cat failures are most lkely due to oil fouling that damaged them . my guess is you use dino oil,,,, the after cat exhaust I would only consider stainless steel and this can be with what ever you wish as the dual out is a nice setup. muffler selection I would consult with the custom muffler shop on what sound you wish. with install make sure you can remove exhaust when the drive train will need repairs//replacing..some times these guys like to weld up the system as one solid piece ..

the oil I use in my vehicles with GM is the 5-30wt or 10-30 wt mobil 1 synthetic. this oil is now dexos GM approved and is with no engine problems with my 1996 and 2000 vehicles. original owner.

make sure you replace the distributor .

98Z
11-17-2013, 11:26 AM
I will be using a full synthetic oil. Not sure yet which one just yet. The engine isn't installed yet and when it is, I'll be running the recommended break in oil for the first couple hundred miles.

Curious, why am I replacing the distributor?

j cAT
11-17-2013, 05:23 PM
I will be using a full synthetic oil. Not sure yet which one just yet. The engine isn't installed yet and when it is, I'll be running the recommended break in oil for the first couple hundred miles.

Curious, why am I replacing the distributor?

these distributors fail at the 175-225,000 mile mark.. bearings and cam gears.

98Z
11-17-2013, 11:42 PM
Gotcha.
I actually did already replace the distributor. I did it because the tabs that the screws went into to hold the cap on were messed up. One was broken, the other stripped out. Last winter I had a crankshaft sensor failure and the shop that I took it to insisted it was a distributor issue, despite the code in the computer. They pulled the distributor to reset it. That's when they found the gear on the new distributor was chewed up really badly for only being in the engine for a few months. This led to the discovery of the camshaft's linear movement. They told me to have the top end rebuilt, I thought rebuilding the top half and not the bottom half as well was silly for a 200K engine... hence the engine rebuild that just happened.

j cAT
11-18-2013, 08:46 AM
Gotcha.
I actually did already replace the distributor. I did it because the tabs that the screws went into to hold the cap on were messed up. One was broken, the other stripped out. Last winter I had a crankshaft sensor failure and the shop that I took it to insisted it was a distributor issue, despite the code in the computer. They pulled the distributor to reset it. That's when they found the gear on the new distributor was chewed up really badly for only being in the engine for a few months. This led to the discovery of the camshaft's linear movement. They told me to have the top end rebuilt, I thought rebuilding the top half and not the bottom half as well was silly for a 200K engine... hence the engine rebuild that just happened.

use a new distributor in the rebuilt engine. I would not use the new one that was with the cam wear issues.

replacing the distributor gear is with some caution as the OEM gear is made of material to reduce wear on the cam gear.

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