Headers on 90 TBI K5

[350K5TBI]

I need a complete new exhaust on my 90. I am using it for plowing. I bought a set of dynomax dual exhaust pipes for it along with a new set of Dynomax headers. I am probably going to put a set of Cherry bomb pro mufflers on it.

My problem is on the Driver's side manifold the Alternator bracket goes over the stock manifold. I am trying to figure out a way around this. I have the serpentine belt drive and would like to keep it that way. It has a fisher plow with the auxilary pump that also attaches but I can find a way to rig that later.

I will also need to put the 02 sensor into the pipe somewhere and was wondering where the best place was.

 

[Justin V]

The O2 sensor on 1990's (at least Suburbans) was located in the driver's side exhaust manifold. If you put yours in the collector area of the header you should be fine.

 

[dyeager535]

Is it just the fact that there will be a gap because the header flange is much thinner than the manifold? Sounds like the earlier power steering setup on that side, and I have headers.

I went to a "real" hardware store, and found a steel spacer. Can't recall what they are really called, but they look like giant roll pins. Make sure it's the right length to make up the difference between the header flange and manifold, then tack weld the spacer where the two edges meet so it doesn't spread when you tighten the bracket to it, done.

 

[tRustyK5]

I need a complete new exhaust on my 90. I am using it for plowing. I bought a set of dynomax dual exhaust pipes for it along with a new set of Dynomax headers. I am probably going to put a set of Cherry bomb pro mufflers on it.

My problem is on the Driver's side manifold the Alternator bracket goes over the stock manifold. I am trying to figure out a way around this. I have the serpentine belt drive and would like to keep it that way. It has a fisher plow with the auxilary pump that also attaches but I can find a way to rig that later.

I will also need to put the 02 sensor into the pipe somewhere and was wondering where the best place was.

Start here on page 22, and continues on the next page.

https://ck5.com/forums/threads/90-k5-project-sanity-8-23-it-lives.263098/page-22

 

[sweetk30]

hate to say this but headers + plow truck = not going to last long at all.

you should see my factory manifolds on my plow truck right now . .

I have a nice light used set to swap on soon from a member hear I got .

 

[350K5TBI]

Cool, any ideas to adapt the stock manifolds to an aftermarket dual exhaust kit? I need to get this thing quiet.

 

[76k5blazerr]

Headers have their place, in my opinion, it's not on a 4x4 or a work truck. I have them on my 72 c10, happy with them. But I would not put them on either of my k5s just because the trouble is not worth the small performance improvement. I don't like how they take up so much room in the engine bay and the main thing is how close most of them run to the starter, you are almost gauranteed to have heat soak problems with headers unless you install a heat shield or do what I did and mount a Ford solenoid up on the fender.

 

[sweetk30]

find local exhaust shop and have them fab up the pipes needed and installed and pay them . faster and TONS LESS BULL CRAP ! ! !

 

[350K5TBI]

The only reason I was looking to go this route was because the y pipe was shot and I found a dual pipe kit for about the price of a y pipe. If it was good I would have put a turbo muffler with a stock tailpipe exit.

 

[sweetk30]

exhaust work just sucks for 95% of us people.

even so called bolt on kits are full of crap when they say bolt on . . .

 

[diesel4me]

Its more work,but I have always just used those parts store elbows to make front pipes to connect to the stock manifolds..

A 45 degree one works for the passenger side,and a 90 degree for the drivers side...you'll need a length of pipe to go back towards the transfer case on both sides..

I used 2" pipe elbows,those fit the 3 bolt flanges I saved off the original Y pipe good,then went to 2-1/4" after that by using an adapter,or just brazing or welding the larger pipe over the 2" one..

The only "hard" part is making the pipes flare where the donut gasket sits,if your truck has them..I have chopped the ends off a Y-pipe and spliced them to the elbows to speed up that part of the job..or had a local muffler shop make the elbows have the correct flare for a low cost..from the front pipes back you can use straight pipe to the mufflers,and oem dual exhaust tailpipes ..

They used to sell direct bolt on dual exhuast kits for stock exhaust manifolds in Walker and Edelebrock brands,and a few others I think ,not sure if those still exist or not..they were around 100 bucks ,if those kits still exist that would be the easier way to go..

Sweet K30 is right though,for most of us crawling around under a truck for a day or more getting rust in your eyes sucks,and the exhaust studs seem to always snap off instead of the nuts coming off,and its a sucky job taking off the manifolds and having to drill & tap the holes...also the kits are sometimes not bent 100% perfect and can be a challenge to install yourself..

 

[Stinky]

Try rockauto for parts. Jegs and or Summit both sell dual exhaust kits for mid 70s trucks. Rockauto may also, search their catalog.

If you have a 3" exhaust, not much advantage to duals.

 

[350K5TBI]

The dynomax kit I bought advertised as being able to be used with the stock manifolds, but when I got it they said I need headers. I have the direct fit headers but realistically am not able to put on headers right now.

 

[Blue85]

More than once I've had a complete exhaust custom bent to my truck for less money than the mail-order kit costs. Plus, expanded and welded is better than clamps and they have to deal with any leaks.

If the only problem is the accessory mounts, just fab a spacer from some conduit, pipe or an old shock hardware kit to make up the difference. It's been done enough I wouldn't be surprised if Summit sells such a spacer.