1966 Factory dual exhaust?
 

Was there ever such a thing as a factory dual exhaust option on the 1966 C20 327 trucks?

If not, is there any way to replicate the factory single exhaust setup? Would exhaust shops have diagrams showing all the correct bends for a factory-correct exhaust setup? Or does anyone have any diagrams or literature showing the correct exhaust setup for a '66 Custom Camper with a TH400 automatic? Thanks!

Re: 1966 Factory dual exhaust?
 

To answer your first question I believe their was such thing as a factory dual exhaust setup. I know that the 6 cylinders only had a single exhaust option. I don't think that chevy did a single on the v8 in the 60's. I may be wrong.

Re: 1966 Factory dual exhaust?
 

Not as far as ive seen. All the muffler books ive seen over the years have only shown a single setup. My 66 327 had a single. Some exhaust shops may have a diagram, but probably not.

Re: 1966 Factory dual exhaust?
 

I have only seen single exhausts through 1966 but the turbo 400 uses the same pipes as a 327 with powerglide. From what I saw the only difference is the single frame mount bracket is about 4" further back on the frame than the powerglide set up. So there is the Y pipe, a long pipe clear back to the muffler and then a tail pipe out the drivers side. Hangers are the one right after the turbo 400 crossmember, one at the rear of the muffler outlet, and one just near the tailpipe end when it angles from the frame rail out past the boxside. I use a great exhaust shop that can custom make all the pipes even in stainless right out at the interstate 80 York exit.

Re: 1966 Factory dual exhaust?
 

Thanks guys. I suspected that only a single exhaust setup was available but I've heard some people say they thought factory duals might've existed. Currently I have aftermarket (cheap) duals and wonder if I will kick myself for returning to the correct single setup with a 3" inlet and 2" outlet (dimensions per Yelmer).

Does anyone know of an exhaust diagram that a guy could get his hands on? Did muffler shops normally have such things back in the day? And would they still exist today?

Re: 1966 Factory dual exhaust?
 

some of the parts books had pictures of the exhaust systems

Re: 1966 Factory dual exhaust?
 

Alot of the parts places that specialize in our trucks offer OEM replacement exhaust that is bent to factory specs, if you're looking to stay original. I know Sharps40 did and install with Walker pieces he got thru a local parts store-seemed to fit good and look correct. Might check out his threads.

Re: 1966 Factory dual exhaust?
 

Would anyone have a scan of the parts diagram that shows a correct setup?

Re: 1966 Factory dual exhaust?
 

Here's directly from the Walker website-

Re: 1966 Factory dual exhaust?
 

Oh, wow. Never would've thought that existed at Walker!

Re: 1966 Factory dual exhaust?
 

They may still be availible too. Check your local Napa.

Re: 1966 Factory dual exhaust?
 

My 66 327 came single, plan to redo it single, with this as a starting point, then let exhaust shop do the rest.

http://www.summitracing.com/parts/wl...del/c10-pickup

Re: 1966 Factory dual exhaust?
 

I checked the 1966 Data book and nothing is listed for duals on any engine . Only thing mentioned is "Standard single exhaust with aluminized muffler" . When you get to Special Equipment it only list duals for ElCamino and passenger cars, no trucks.

Re: 1966 Factory dual exhaust?
 

If you find an older exhaust shop- they used to have "bend cards" for alot of applications, and they'd offer mirror image dimensions to make duals with.

I know the old Ben Pearson brand of pipe benders had a card system like that.

if you local store doesn't have the walker, they shold be able to use the numbers to cross referrence it.

Glad what I found could help a few.

Re: 1966 Factory dual exhaust?
 

Up until around 1972, most auto parts stores carried application specific exhaust pipes and tail pipes. The pipes were the most recognizable items in the store because there were large racks of them either visible in the back, or out front lining a wall. Fan belts were also normally displayed this way. I’m sure the pipes were produced by a large wholesaler like Walker. They generally had dual exhausts available for just about everything, because it was an easy to sell upgrade feature for guys that liked to inexpensively “fix up” their own cars.

The same was true at Sears. They offered singles and duals up until around 1972, when they discovered single mufflers lasted up to twice as long as dual mufflers because they warmed up faster and burned out all the moisture sooner, extending the life of the muffler. So overnight they discontinued sales of dual exhaust systems throughout the entire Sears chain. I got that input from a Sears Automotive store manager.

I only mention this because a dedicated search of Ebay or automotive literature sales of old exhaust manufacturer counter catalogs could potentially turn up printed proof that dual exhausts may have been offered in the aftermarket for our series of trucks.

Re: 1966 Factory dual exhaust?
 

seems you can get the y-pipe, muffler and tail pipe made by walker, but no intermediate pipe. at least i can't find it or a # for it. have an e-mail in to walker. will post if the reply.

Re: 1966 Factory dual exhaust?
 

Don't want to burst your excitement here but for reference, I have 2 new of those Walker Y pipes, 2 of the Walker round mufflers, and one Walker tailpipe of those part numbers sitting here in my shop that I had purchased a while back. They don't make the exhaust center section piece anymore either. Note that these are only for a "283" and as such the pipe size on the Y is only about 2" and the muffler outlet is only 1 7/8 along with the tailpipe. That was the 283 specs. The 327 engine Y pipes from what I have taken off of several 327 trucks, went from 2" to 2 1/2 inch tubing right in the Y pipe and just below the 2" rams horn manifold. The exhaust pipe was also 2 1/2" pipe and the muffler was round with 2 1/2 inlet and 2" or 2 1/4 inch tailpipe out from the muffler but I have to check that last measurement to be sure.

I planned to actually build a 2 1/4 inch factory looking dual exhaust system with a pair of stainless steel mufflers tucked under the bed floor and have my exhaust guy use that new Walker 1 7/8ths tailpipe I have as a pattern to muster out a correct appearing set of L & R tailpipes. That Walker tailpipe has some interesting and wild sharp bends in it getting around the coil springs and going straight back under the rear frame rail till it sports off at a 45 degree straight dump.

Re: 1966 Factory dual exhaust?
 

Sorry... I misspoke about the correct muffler and pipe dimensions. The stock setup was 2" from the manifold becoming 2.5" at the Y-pipe and into the muffler. Then exiting the muffler at 1.75" (or is it 1 7/8"??) all the way to the tail pipe. Thanks for the corrected info, Yelmer!

Re: 1966 Factory dual exhaust?
 

Patience is the key. Just about everything makes it's way to ebay eventually.
This NOS tailpipe, and a six cyl exhaust pipe were listed and sold several weeks ago. Just keep watching...

http://www.ebay.com/itm/NOS-60-66-CH...p2047675.l2557

Re: 1966 Factory dual exhaust?
 

Here is what the "OLD MAN" at the shop did. This is a 1962 short bed. I even got a "back in the day..." story. Better than the 20+ year old Patriot sidepipes. I had no idea where the pipes went. Side note the 75 Suburban 454 I had did have factory duels per smog sticker and pipe map. 40 ft of pipe
http://carphotos.cardomain.com/ride_...006_medium.jpg

http://carphotos.cardomain.com/ride_...007_medium.jpg

Re: 1966 Factory dual exhaust?
 

Re: 1966 Factory dual exhaust?
 

Dont use anything smaller than 2 1/4" pipe or you'll choke that motor. I'm running 2 1/4" dual set up with small glass packs on my 283 with HEI and Edelbrock carb and I wish I would have used 2 1/2" pipe..

Re: 1966 Factory dual exhaust?
 

From what Im reading in the parts book "
Crossover GM Part Number 65 66 327 only 10 and 20 series 3873120
crossover to muffler 3873124
Muffler 3981946
Tailpipe 3820975
http://i270.photobucket.com/albums/j...7/untitled.png
http://i270.photobucket.com/albums/j.../72TL_0492.png