Aftermarket Cats

[98silvyman]

I've got a 1998 Silverado with the 5.7L Vortec. The cats are bad and i'm curious as to what you guys recommend as far as replacements. I keep hearing that it's really hard to replace them with aftermarket ones on this truck.

I saw some Dynatech PowerCats in my latest Summit Racing catalog and those have caught my eye. Anyone got them?

Thanks in advance.

[drummer_boy51]

Thunderbolt Cats....I have them on my 98 5.7L and they're amazing....and cheap lol. I say them or just cut em off

[98silvyman]

Here is a link to the Dynatechs

http://www.summitracing.com/search/B.../?autoview=SKU

[98silvyman]

Thunderbolt Cats....I have them on my 98 5.7L and they're amazing....and cheap lol. I say them or just cut em off

Ok i'll look into them. Did they make your truck any louder? Any performance differences? I would cut em off but dad says no and quite frankly i'm not willing to pay the fine

[drummer_boy51]

Yeah they made it a little louder...also toned my exhaust a little more. I really like them and have been happy with them. They were like $55 a piece for me from www.performance-curve.com

[Okimaw]

I have the same engine, 97 Sierra. My cats and piping were all shot so I ended up getting a direct fit setup from magnaflow. Like drummer boy stated it makes it a bit louder and changes the tone for the better. I was going to switch out my flow pro mufflers because I wasn't happy with them. Now they have a deeper throaty sound that I like. You can pick it up on summit for $350 or so

[98silvyman]

Thanks for the input i'll keep looking into these

[gatortrax]

40 bucks on ebay

[94_c/1500]

I have dual Thunderbolts on my Sierra and my Scrambler. I have no problem with them.
I didn't have any cats on my Scrambler for about a week, after I had them installed, the exhaust sounded the same as it did before it had cats.

[tiresmokindad]

I've got a 1998 Silverado with the 5.7L Vortec. The cats are magnaflow catalytic converter bad and i'm curious as to what you guys recommend as far as replacements. I keep hearing that it's really hard to replace them with aftermarket ones on this truck.

I saw some Dynatech PowerCats in my latest Summit Racing catalog and those have caught my eye. Anyone got them?

Thanks in advance.

My eyes were also caught by that. I have Dynatech PowerCats. I purchased it last month. I will post some pictures of it once they are available. :)

[stockchevy1983]

I have the same engine, 97 Sierra. My cats and piping were all shot so I ended up getting a direct fit setup from magnaflow. Like drummer boy stated it makes it a bit louder and changes the tone for the better. I was going to switch out my flow pro mufflers because I wasn't happy with them. Now they have a deeper throaty sound that I like. You can pick it up on summit for $350 or so

if u go to monsterautoparts.com, the magnaflow y pipe with cat is 206 shipped as suppose to 300 from summit or jegs.

[stockchevy1983]

I have the same engine, 97 Sierra. My cats and piping were all shot so I ended up getting a direct fit setup from magnaflow. Like drummer boy stated it makes it a bit louder and changes the tone for the better. I was going to switch out my flow pro mufflers because I wasn't happy with them. Now they have a deeper throaty sound that I like. You can pick it up on summit for $350 or so

if u go to monsterautoparts.com, the magnaflow y pipe with cat is 206 shipped as suppose to 300 from summit or jegs.

[98silvyman]

I haven't been on awhile. i'll look into the magnaflow y-pipe thing and the pics would be great!

[loudchevyZ71]

if you don't have emission testing, and I'm assuming in Colorado you don't, I would just run a pipe through the cats.

[stockchevy1983]

I haven't been on awhile. i'll look into the magnaflow y-pipe thing and the pics would be great!

well in my state i have emissions so i always try to do the best setup i can. here is pic of magnaflow y pipe with new cat.



primaries are 2 and 7/8 i believe and the pipe after cat is a lil over 3''

[Tigwldr]

Have you looked into Magnaflow spun cats?
http://www.summitracing.com/search/?...nverters&dds=1

[smokedrail]

I have 2 brand new B&K high flow cats 2.5" If anyone is interested.

[98silvyman]

if you don't have emission testing, and I'm assuming in Colorado you don't, I would just run a pipe through the cats.

on occassion (seems to be more during the summer) there are trucks parked on interstate entrance ramps in denver and colorado springs and i frequent both so i'm gonna have to put cats on.

Have you looked into Magnaflow spun cats?
http://www.summitracing.com/search/?...nverters&dds=1

i have not seen these yet. shops are quoting me 500-900 dollars to put them in so now i'm looking into picking up a welder and doing it myself.

[Tigwldr]

i have not seen these yet. shops are quoting me 500-900 dollars to put them in so now i'm looking into picking up a welder and doing it myself.

You should check them out. I have 2 59956 cats. They are small and look fantastic as ussual with any Magnaflow product (I should be a spokesperson for maggy, lol)
This is how they will be fit into my system. The muffler of choice is a 12568 di/do w/built in x-pipe. It is a larger case muffler but with the headers cats and all run through 2.5" SS tubing it should sound great. Oh, it will be exiting in front of the passenger wheel/tire.


$500 to 900 to install cats, I'd suggest looking for a new shop. Or like said, pick a decent welder and do it yourself.

[98silvyman]

$500 to 900 to install cats, I'd suggest looking for a new shop. Or like said, pick a decent welder and do it yourself.

Ya 500 dollars is the cheapest i've found thus far at any shop a reasonable distance from me and its the one where i had my duals put on. i've got a year of welding experience so i know i can do the job just fine so now the hunt is on for a welder... but which one? It'll probably be red or blue