1972 k20 4x4 exhaust system
 

Looking for suggestions on the best fitting exhaust system for my 72 k20 4x4 with sbc 350/th350 and np205. I’ve looked and most seem to be just for the 2 wheel drive trucks. What has everyone ran?

Re: 1972 k20 4x4 exhaust system
 

Ya, wouldn't that be nice. A mandrel bent 2 1/2" stainless with stock rams horn manifolds for a long bed.....I guy can dream can't he......

Re: 1972 k20 4x4 exhaust system
 

Try waldron's exhaust

Re: 1972 k20 4x4 exhaust system
 

I bought a 2-1/2" Heartthrob dual system for my 2WD and am pleased with it. They also make a system for a K20s. The pipes are mandrel bent. Systems are available for 4X4s with behind the wheels or rear exits and with "stock" (#4149SK and or #1014149...actually fairly loud) or glass pack mufflers (#4149GP or #1024149). The part numbers starting with 101 and 102 are rear exit.

I got mine from Auto Accessories Garage with free shipping (https://www.autoaccessoriesgarage.co...SABEgI42vD_BwE)

The Heartthrob website (http://www.heartthrobexhaust.com/manifolddualkits.htm) says the system won't work with a Rockwell transfer case.

Perhaps someone here has some personal experience with the 4X4 system.

Re: 1972 k20 4x4 exhaust system
 

Mine was custom made at a local exhaust shop. Dual pipes to Magnaflows, then dumped ahead of the rear axle.

Re: 1972 k20 4x4 exhaust system
 

I know its not a bolt in kit, but i ordered a mandrel bent pipe kit and did it my self and I am pretty pleased.

Re: 1972 k20 4x4 exhaust system
 

I installed their exhaust in my 1970 (chassis) K10 4X4 with an SBC and stock ramhorn manifolds.

My biggest challenge was clearing the NP205 transfer case. To do that I had to shorten the passenger side down tube about 2-3 inches, as well as do a lot of fussing with the mufflers and hangers. I can't say it wasn't challenging (aka PIA), but after a fair amount of trial and error I think it came out okay. The pipes are long enough for a long bed, and have to be shortened just before the mufflers for my short bed. I am using the stock type mufflers and think they sound pretty good.

-Steve

Re: 1972 k20 4x4 exhaust system
 

I always patronize my local exhaust shop to get a custom-fit system done how I want it.

Re: 1972 k20 4x4 exhaust system
 

The Good thing about the Heartthrob kit is it's mandrel bent so you end up not losing flow.
Ron

Re: 1972 k20 4x4 exhaust system
 

Believe it or not...I used the kit from LMC....side exit behind the wheels with turbos....worked really well for something I could do at home.If I was going to do over I would do the rear exit instead

Re: 1972 k20 4x4 exhaust system
 

From where? Was it stainless?

Re: 1972 k20 4x4 exhaust system
 

Give it up man, what shop. I'm in WV, so I might trailer it there.

Re: 1972 k20 4x4 exhaust system
 

This^^^

Done this on every vehicle I’ve ever owned. Custom fit, never any disappointments, and way less $$$ than a pre made kit.

Re: 1972 k20 4x4 exhaust system
 

No decent exhaust shops around me, so I built one with a universal kit from Speedway. I can post more pictures when I get home.

Re: 1972 k20 4x4 exhaust system
 

Thanks guys . I’ll call a couple local exhaust shops first . I could make my own with a universal kit as well, just short on time as usual.

Re: 1972 k20 4x4 exhaust system
 

Mandrel bent and stainless is a lot of hype. You will never notice the "loss in flow" and stainless usually contacts mild steel somewhere. The current aluminized custom built local system I have was done in '04 and the truck runs as good and sounds as good as can be. My camper hauler got a system in '89 and was still on it in '04 when I stopped running it. Isn't 15 years long enough to satisfy?
It's been a while but I want to do something different this summer with exhaust. I used Tire Mart in Frederick, MD last time. I need to check who is doing exhaust now. There are exhaust shops all over. There is a guy in the area that does custom mandrel bent systems, but very very expensive. I have a Bartens bumper, a swing down spare carrier, and hitch bracing. I had them dump it out the rear quarter under the bumper

Re: 1972 k20 4x4 exhaust system
 

Come on Tim, stainless is what I want, I'm not asking how to build an exhaust system I'm asking you to give up the names of the shops you mentioned in this post. Tire Mart, that's your custom shop? Who is the very, very expensive shop? Mandrel bent will flow better and it isn't hype. Would you put 1" headers on a big block or 1 5/8"? Why not be helpful?

Re: 1972 k20 4x4 exhaust system
 

Tim, I like the way yours sounds. ......nice!!.....

Re: 1972 k20 4x4 exhaust system
 

I thought I was being helpful.I didn't tell you how to build an exhaust and I gave you the name of where I've had the last few systems done... in aluminized that averages 15+ years. Talk to Mitch at Tire Mart. I have also used Commercial Tire in Elkridge, MD and Damascus Tire in town of same name. Ben Woo does the mandrel stainless but I've never wasted my money on that. He's in Montgomery County, MD. I think in the airpark in Gaithersburg.

My truck with 350 has Hedman Torque Step full length headers into 2 1/4" pipes and is anything but choked out. It's just right, a very happy truck. Sounds like you're sold on the hype and that's your right. I use my truck and it does everything I ask it to do with style and ease. People debate the negligible gain from headers, which are mandrel bent and the same holds true for the rest of the exhaust. I'm not worried about 5 hp. It's not a race car

Thanks Dale

Re: 1972 k20 4x4 exhaust system
 

I used stainless works and cut 1 of the tubes to twist it a little bit but all the rest worked great and clears everything

Re: 1972 k20 4x4 exhaust system
 

Did you order a kit? Is your K20 a long bed?

Re: 1972 k20 4x4 exhaust system
 

Yes it is a long bed and yes it's a kit from totally stainless..if you look In my build thread i did cut 1 tube and twist it a bit cause i got a blazer tank

Re: 1972 k20 4x4 exhaust system
 

And its 3" not 2 1/2"��

Re: 1972 k20 4x4 exhaust system
 

I'm assuming you meant Stainless Works out of OH. Do you have a kit part number that you ordered? I can't seem to find a 4X4 version on their site.

Re: 1972 k20 4x4 exhaust system
 

Do you guys run the passenger side pipe above or below the (NP205) T-case?

The fuel lines drop out of the cab in that same area and I'm trying to figure out how to route my exhaust to keep it away from the fuel line. Right now I have it going under the T-case but it hangs down below everything.

Re: 1972 k20 4x4 exhaust system
 

It routes over the t-case. Not much room with 2.5"

Re: 1972 k20 4x4 exhaust system
 

Stw-CT6773TS is the part # I looked back and I ordered it from summit after talking with stainless works on which kit would work. Look on my build thread on how I routed it. Good luck:metal:

Re: 1972 k20 4x4 exhaust system
 

All K/20s are long beds. Only 1/2 tons were offered in SWB
I always have it run over the the crossmember between the transfer case and frame. One thing I always make clear when getting my exhaust done is nothing is to hang below the frame... nothing. I run full length headers and they are up above the frame bottom, so no reason the rest of the system can't do the same.

Re: 1972 k20 4x4 exhaust system
 

I called Stainless Works yesterday. The 3" kit they have for our trucks is set up for headers (like yours) OR a 2 1/2" kit is set up to attach to stock 2" outlet rams horn manifolds. There is no option to attach to the 2 1/2" high perf manifolds. Pretty disappointing. I also looked at the Heartthrob system and they only offer aluminized steel in 2 1/4". So a dead end there also (for 2 1/2"). It looks like a custom system is in my future if I want 2 1/2" mandrel bent stainless. I found this shop in MD http://mandrelbendingsolutions.com/.

Re: 1972 k20 4x4 exhaust system
 

Which manifolds do you run ?

Re: 1972 k20 4x4 exhaust system
 

2 1/2" outlet rams horn ( I believe they were off of a 67 vette).

Re: 1972 k20 4x4 exhaust system
 

I'm getting ready to put a new exhaust system in my '71 K20. Currently it has ramhorns on it, which I am okay with. However, to the best of my knowledge they are from a square body era truck (pic shown below). Would you guys replace the manifolds prior to having new exhaust ran or run them as is? Not really wanting to spend the extra money on new manifolds but also don't wan't to have my new exhaust routed to manifolds I will be wanting to change in the future...

Re: 1972 k20 4x4 exhaust system
 

Those aren't ramhorns. I would change to the ramhorns.

Re: 1972 k20 4x4 exhaust system
 

Would you mind providing a link with which ones you would go with and where you would get them from? Maybe some others will chime in as well.

Just want to get the proper fitment (rear dump, center dump, etc) for a 4x4.

Re: 1972 k20 4x4 exhaust system
 

Use the search function at the top of this page next to your user name (just to the left). Select the 67-72 chevytrucks.com button. Enter in "rams horn". I did this yesterday and there are piles of threads you can read through.

Re: 1972 k20 4x4 exhaust system
 

1971 K20 will be same as a 1972 K20 and use center dump ramhorns.

Re: 1972 k20 4x4 exhaust system
 

They are straight center dumps too

Re: 1972 k20 4x4 exhaust system
 

Indeed they are.... I was only thinking of center vs rear dump, didn't even think about straight vs angled. Thanks for the clarification! :chevy:

Re: 1972 k20 4x4 exhaust system
 

Sorry it took so long to respond, I got my 2.5 inch mandrel bent kit from MA Performance, for some reason it took them a long time to get the order sent out, but once I got it I can say I am pleased with the product. I choose the kit because it was 16 Gauge wall instead of the 18 gauge stainless and it was 304 Stainless instead of the more popular 409 stainless. I recently learned about the classes of stainless and the 400 class stainless (which most exhaust is made from) is more corrosion resistant than steel but it surface rusts over time given the conditions. 300 class stainless is the most corrosion resistant and is a higher quality stainless. MA performance claimed the kit was made by squirrelly performance. They offered a couple different sizes of kit and individual bends as well which i thought was neat. I used Magnaflows for my mufflers. and I can say it has turned out really nice so far. I will try and get some pictures taken and posted.

Re: 1972 k20 4x4 exhaust system
 

Are the straight center dumps you see on eBay or amazon that go for around $60 per side decent enough quality for a driver?