Cali,68,L-79

Paul I'm looking at the Walker chambered exhaust you bought and have a few questions.

1. Ecklers sells the manifolds but I am unsure of the correct casting #'sManifold, Exhaust RH 2" SB (casting # 3932461)
or
Exhaust Manifold, LH 2.5" 300/350/365hp casting #3846563

2. do I need the 2.5' or 2" everyone here has the male prevado saying bigger is better however a small 327 may not need 2.5" and the engineers at GM didn't think so. Remember I have the L-79 with a big cam.
It appears the 2" fits dead stock utilizing the stock hangers but the 2.5" requires a speacial hanger just aft of where the pipes go thru the frame. What mods were required (assuming you went 2.5")

3. Did the pipes fit stock or was "machining" required?

4. After tightening the U-clamps did you have a welder/ muffler shop tack weld the unions for insurance?

5. Did the exits come out perfectly even out of the rear exhaust valance or did you have to 'mod" it to come out perfectly?
6. As the chambers are dead under your butt and not in the rear as mufflers would be did you have to put some flashing on the body or do you feel increased heat in the cabin?

Appreciate the assist.

David

Missileman

Some info:
Ecklers castings are not GM, some aftermarket company (China, I believe). Lots of casting flash and the shaky head mounting surface will probably require a gasket.
GMPartsDirect manifold is real GM (Mexico) with excellent quality for $10 more (and yes, their high shipping) but they were worth it.
As for manifold size, are you going to be running 7K RPM all day for a 500 mile race? If so get the 2.5". The 2" with your motor will give better low end torque for the RPM range that you (and possibly your wife also) will be using the majority of the time.
Just my $.02

Paul L

David,
The chambered system is from Allens Stainless Steel in Logansport, Indiana. It is 2" which is just fine for the touring-type driving I do. I have no basis of comparison to a car with a 2 1/2" system unfortunately. It is my understanding that the smaller diameter works to increase low-end torque and I certainly need that with the Powerglide.

I hesitate to be specific on the fitment questions as the system was on the car when I bought it. Hopefully the former owner (EdT) will see this thread and respond. The chambers are under the seats but I have not noticed any heat issues. Of course I went from a 1979 with a catalytic converter to true dual exhaust! Those cat cons get very hot.

I believe the 3932461 manifold was used on the right side for SBs from 1969 to 1971 and on both sides from 1972 to 1980. The numbers I have for 1968 are 3872765 (left) and 3872778 (right). I am not familiar with the Eckler's offering but there certainly are unmarked Chinese-made castings on the market.

Cali,68,L-79

I'll be just touring. So 2" should work. Paul mentioned his was stainless and I see no mention of the type of steel used.

<img src=" http://content.madirect.com/img300/fr1293.jpg " border=0>
Mid America is proud to offer our Performance Choice Undercar Chambered Exhaust. Walker Manufacturing, who produced the original side exhaust for Chevrolet, has supplied us with a special, chambered pipe section similar to the ones used from 1965-67. Our technicians built an undercar dual exhaust system utilizing these chambered sections. This 2 1/2" system fits in the stock location with no modifications and utilizes your stock extensions, exiting through the rear valance panel. The 1974-up systems are supplied with turn-downs similar to the stock muffler tips. The chambered sections give a deep, powerful side exhaust burble at idle and cruise speeds, easily allowing conversation or stereo listening. But when you "stand on it", your Corvette will have that great side exhaust growl! State year, 2" or 2 1/2" exhaust manifolds, transmission, and with or without tool wells (on 1963). Fits 327 & 350 engines or 396/427 big blocks. Comes with clamps and manifold gaskets.
603-856 1968-73 Undercar Chambered Exhaust, manual trans, small block $299.99 In Stock

JRD77VET

This is the same system I have on my '77. MAD does NOT offer a stainless steel system.

Allen's does offer a s/s system. http://www.allencorvetteexhaustsystems.com/

:seeya Jeff

Paul L

David,
My system is not SS despite the name of the company that provided it. I like the former owner of my car have bad habits: we polish the undersides of our cars. In fact I did so today. When you only drive about 1,000 miles per year this preserves the runnng gear to as-new standards. I will be criticized for being **** about my car but it is a hobby. I spend more time fooling about than driving. My former 1979 saw rain twice in 17 years.

Cali,68,L-79

Jeff and Paul the $725 is above my buget and Susan's carpet is not even in yet for spring. :rolleyes: for that price I might as well spend an extra $100 for side pipes or try the non stainless unit from MA.

BTW Paul the 77's suspension was a work of art and my billet aluminum oil pan, don't ask, was polished monthly. I'd cringe if I had to run over a puddle of water. Now between the job, and remodeling the house I do what I can do, it's been a month since I even popped the hood on the motor, hope it's still there, assume so it's still running good.

Wow do priorities change. :nonod:

JRD77VET

I went with the $299 system from MA. I ( and my wife :thumbs: ) love the sound of the chambered exhaust.

I had my mechanic put it on for me and he said it was an easy install. The ony "problem" with mine was the reverse switch was in the way. I now have a toggle switch.

Keep in mind that the '77 didn't have duals originally.

:seeya Jeff

Cali,68,L-79

jeff sounds the way to go. Has it been holding up or is there surface rust forming, be honest please. Hope my reverse switch is not in the way.

Paul L

David,
The aluminized system that I have is $399. But I know where you are coming from. Our hardwood floors are re-done as well as carpets but I just signed a contract for a $7,000 interlocking stone driveway. That followed a furnace upgrade last winter. You may remember my post re -40F! There are more money pits than Corvettes! But things are coming into perspective: it is almost time to drive....


[Modified by paul67, 9:42 PM 4/30/2004]

Cali,68,L-79

Ed t, all thanks for your input. I assume none stainless is aluminized not pot steel junk,

Paul L

This pic shows the welds and the heat wrap Ed is mentioning. The only change I made after the pic was taken was to install SS clamps.



And here is his rear clamp.




[Modified by paul67, 9:12 AM 5/1/2004]

Eddie 70

David, I put an Allens aluminized exhaust system on my vette and it still looks like it did when I put it on over 4 years ago. I was worried about same thing you are, the ugly rust. So far in over 5000 miles no rust and it still looks good. I would recommend Allens to anyone thinking about getting a new exhaust system. I installed mine in the garage by myself and it was no problem at all.

Paul L

The pipes are a little dirty (I got caught in the rain last week) but still free of rust.

Cali,68,L-79

I noticed Eddie said he installed his by himself in the garage. I will be doing the same. Did you tighten eerything up then take it to a welder to put tack welds on it for piece of mind? I remember 5 years ago my Mother was visiting and my exhaust I installed fell off just aft of frame holes, both sides. The welder at Midas told me you can use clamps so you can remove at any time to get access to your tranny, rear end and rear spring but you must tack weld becuase vibration over time will cuase the ends to slip out. I can use a Dremel to grind off the tack welds if I need to do maintenance however that tack welding will be the source of any rust forming. Catch my dilema?

P.S. hwat's the difference between Alum-1 and Alum-2 asdie from $25??


[Modified by Cali,68,L-79, 11:35 AM 5/1/2004]

Paul L

David,
Here is a pic of the front weld.