70 exhaust mis-fit, L46 4 spd.

[Bill L.]

Well I finally got around to installing the exhaust system from a well know recommended vendor.

The short piece of pipe on the passenger side that the tip slides over is 5" on the passenger side and 4" on the driver's side. What is the correct length? Wish I had noticed before mounting it in place.

A 1/2" or so would be okay. Should I try cutting the longer side? The problem is that the tip starts to hit the bent portion of the pipe and It really will be difficult to get good alignment on the tip.

Thoughts? I had the system sitting for almost two years before installing.


Bill

[Joe L.]

Re: 70 exhaust mis-fit, L46 4 spd.

Well I finally got around to installing the exhaust system from a well know recommended vendor.

The short piece of pipe on the passenger side that the tip slides over is 5" on the passenger side and 4" on the driver's side. What is the correct length? Wish I had noticed before mounting it in place.

A 1/2" or so would be okay. Should I try cutting the longer side? The problem is that the tip starts to hit the bent portion of the pipe and It really will be difficult to get good alignment on the tip.

Thoughts? I had the system sitting for almost two years before installing.


Bill

Bill------


The correct length is about 4-1/2" from the muffler end plate to the end of the extension. The extensions should not be "straight". They have a slight downward bend (as installed on the car).

[Dick W.]

Re: 70 exhaust mis-fit, L46 4 spd.

I bought many systems from all the vendors that were in business when you bought your system. I NEVER installed one that did not require modifications of some sort. Sometimes I had to take the pipes to the muffler shop to be re-bent. Every time you complained to the vendors, it was a "so what" attitude. Thank goodness there are manufacturer's today that have systems that fit like the factory installed them.

[Bill L.]

Re: 70 exhaust mis-fit, L46 4 spd.

HI Dick,

I am assuming you mean Gardner. They did not have the system they have now two years ago. Wish they had.

I may end up biting the bullet and buying one from them.

I bought mine from the vendor most recommended at the time.

Am I having fun yet


Bill

[Greg L.]

Re: 70 exhaust mis-fit, L46 4 spd.

Bill,
I bought a complete carbon steel exhaust for my 69 427, auto from Corvette Central about 4 years ago and installed it about 2 years ago so like you I couldn't return it either.

The passenger side fit PERFECT with no alterations. However the drivers side was poor at best. Actualy it wasn't even poor because I couldn't even join the two pipes! The front pipe had to be cut and rewelded to change the angle just ahead of the joint at the trany mount. The rear pipe/muffler assy looked "okay" but I could see that it was puling the rear hanger about an inch or so forward. I thought it would be okay but once the body was back on I knew I had to mod it too.

This pipe was good until just after the strut rod mount, then the last two bends were too tight. I had to cut the pipe at the bends most of the way through and then pull the muffler aft to position it properly then I tack welded the pipe and did a proper weld and metal finish so you can't see where I altered it. Then I noticed the the tailpipe angel was wrong so I did the whole process again aft of the muffler to get the tail pipe to look proper.

It was alot of work and the set should have been returned but at the time it was as close as you could get to original. Since it was carbon steel I knew I could make it work so I couldn't justify trashing the whole system for a new Gardner kit.

This is typical for ALOT of reproduction parts that I could rant on for hours because in my books they don't even qualify as a service replacment part because the parts don't even fit let alone are a reproduction of the original part they are supposed to replace.

You are no alone with your frustrations but if you have the time, a welder and they aren't aluminized then you can do what I did and it will work and look good when you are finished.

Just curious, has anyone tried the Gardner kits yet to see how they fit and judge on the early C3's?

[Bill L.]

Re: 70 exhaust mis-fit, L46 4 spd.

It is Corvette Central.

I have sent an email. The frustrating thing is that I am truly a do it yourself hobbyist but with a somewhat limited budget. I do not have a garage full of tools to fix their stuff and make it right.

I have wasted more time and money on improper fitting stuff from most of the vendors. I ask a LOT of questions before spending the money and still do not get what I think is decent quality.

In this case it is just very poor quality control. I have spoken with others who bolted up their CC exhaust with no problem. Let's see what happens.

Bill

[Joe L.]

Re: 70 exhaust mis-fit, L46 4 spd.

Bill,
I bought a complete carbon steel exhaust for my 69 427, auto from Corvette Central about 4 years ago and installed it about 2 years ago so like you I couldn't return it either.

The passenger side fit PERFECT with no alterations. However the drivers side was poor at best. Actualy it wasn't even poor because I couldn't even join the two pipes! The front pipe had to be cut and rewelded to change the angle just ahead of the joint at the trany mount. The rear pipe/muffler assy looked "okay" but I could see that it was puling the rear hanger about an inch or so forward. I thought it would be okay but once the body was back on I knew I had to mod it too.

This pipe was good until just after the strut rod mount, then the last two bends were too tight. I had to cut the pipe at the bends most of the way through and then pull the muffler aft to position it properly then I tack welded the pipe and did a proper weld and metal finish so you can't see where I altered it. Then I noticed the the tailpipe angel was wrong so I did the whole process again aft of the muffler to get the tail pipe to look proper.

It was alot of work and the set should have been returned but at the time it was as close as you could get to original. Since it was carbon steel I knew I could make it work so I couldn't justify trashing the whole system for a new Gardner kit.

This is typical for ALOT of reproduction parts that I could rant on for hours because in my books they don't even qualify as a service replacment part because the parts don't even fit let alone are a reproduction of the original part they are supposed to replace.

You are no alone with your frustrations but if you have the time, a welder and they aren't aluminized then you can do what I did and it will work and look good when you are finished.

Just curious, has anyone tried the Gardner kits yet to see how they fit and judge on the early C3's?

Greg------


I had exactly the same problem but with an Allen's set of 2-1/2 stainless steel pipes. The passenger side fit PERFECT. The driver side was a nightmare. The real problem was the driver side FORWARD pipe. That's what created all the problems with proper fitment of the rear pipe. I sent the left side forward pipe back to Allen's and they adjusted it, but it still wasn't right.

Next, I purchased a 1970-74 left side forward pipe from The Stainless Works (and changed the left side exhaust manifold to the 70-74 piece). It was worse in several ways. So, I went back to the 66-69 manifold and decided I needed to further adjust the Allen's pipe.

I didn't want to go back and forth to a muffler shop trying to get this right, so I purchased the below-pictured from Harbor Freight. It was not real cheap, even from them, but it did the job. You can't really do any major sort of bending (like fabricating exhaust pipes from straight tubing) with this because you'll "kink" the tubing if you do. However, you can make the minor adjustments which are usually all that's required.

[Greg L.]

Re: 70 exhaust mis-fit, L46 4 spd.

I feel for you Bill but there isn't much we can do about it. I've had good and bad parts from all the major vendors and to be fair to them they don't really have much if any quality control on parts they just buy and sell(hence the name vendor)! However what sets the reputable ones apart from the shady ones is their after sales customer service. Without getting into it Paragon(yes I know alot of members like them) gave me the worst after sales service I could ever imagine but on the flip side DR. Rebuild gave me the best. I hear he can be a tad crusty at times but my impression was that he was a straight shooter and if you don't jack him around and waste his time he'll treat you the same. Even the "big guy" at Paragon(David I think) had no problem jacking me around and wasting my time due to their shipping screw-up even after I placed a very large order and had lots more to come as I was just starting my body off resto. I was ticked and still am but he is the one that lost as the next several thousand dollars in parts were spent elseware!

It's not just the vendors either. I got ripped off really badly from an NCRS member that answered my ad in the Driveline looking for good dated door glass. What a crook he is too but I digress... Sorry to rant but I think I'm as ticked about your exhaust as you are because it brings back lots of bad memories!

I hope it turns out well for you.

[Greg L.]

Re: 70 exhaust mis-fit, L46 4 spd.

Hi Joe,

Well that's a much better idea than making several trips back to muffler shop!

Does it work to "open" a bend too or can you just make them tighter?

My pipes problem was actualy just aft of the rear strut mount because the flat spots in the pipe were placed evenly right at this point. Had I moved the rear pipe farther aft then this flat spot wouldn't have aligned up with the mount.

Since you are a 69 guy too I have a quick question. Did the 2" pipes have this flat spot? I though only the 68 and 70 and on with the 2 1/2" pipes had this flat spot.

[Joe L.]

Re: 70 exhaust mis-fit, L46 4 spd.

Hi Joe,

Well that's a much better idea than making several trips back to muffler shop!

Does it work to "open" a bend too or can you just make them tighter?

My pipes problem was actualy just aft of the rear strut mount because the flat spots in the pipe were placed evenly right at this point. Had I moved the rear pipe farther aft then this flat spot wouldn't have aligned up with the mount.

Since you are a 69 guy too I have a quick question. Did the 2" pipes have this flat spot? I though only the 68 and 70 and on with the 2 1/2" pipes had this flat spot.

Greg------


The tube bender will work either to increase or decrease the bend angle. You have to set the roller locations (controlled by the pins and the various holes for them you see in the upper part of the tool) to whatever is necessary for the bend you need. This would be a little tedious if one were doing a lot of bending with this tool but for the kind of adjustments we make, it's no problem, at all.

The REAR 2" exhaust pipes on my 1969 were originally flattened. The REAR pipes were the same for small block and big block for 1969. In previous discussions on this subject quite a few folks questioned this. In fact, I even started to doubt my own recollection. However, I have now seen the GM specs for the 2" pipes, albeit the ones used from 1963-67, and these call for the rear pipes to be flattened for a considerable length, just like I remember on my 1969 pipes. I have every expectation that the specs for the 68-72 2" pipes would be the same in this regard.

I'll be posting some more information on exhaust pipes when I can get around to it.

[Bill L.]

Re: 70 exhaust mis-fit, L46 4 spd.

Thanks for all the input.

Joe,

Is my best move to take what I have and ask a muffler shop to cut off the small outlet pipe, cut it down and re-weld?

If the tip did not run in to the bent portion of the pipe, I would just cut it down


Bill

[Joe L.]

Re: 70 exhaust mis-fit, L46 4 spd.

Thanks for all the input.

Joe,

Is my best move to take what I have and ask a muffler shop to cut off the small outlet pipe, cut it down and re-weld?

If the tip did not run in to the bent portion of the pipe, I would just cut it down


Bill

Bill------


It's hard to say what the best course of action would be here, especially without seeing the actual parts. It actually surprises me that with these extension pipes only + or - 1/2" from original that there would be any problem with fitment or adjustment of the tips.

[Bill L.]

Re: 70 exhaust mis-fit, L46 4 spd.

Hi Joe,

Me too. However, the extra length does not allow for the tip to go on far enough and because of the bend it starts to twist a little so it does not come out straight.

I was told the tip should only stick out about 1/2"-3/4" past the opening. I can get it to about 1" before it starts to twist. Since the other side is so much shorter it wants to be sticking out about 1/2". I might be able to compromise at 3/4" but it looks like the driver's side starts to twist so the tips are crooked.

If I did not have to tap the passenger side tip to get in on far enough I would not be so concerned. I spent $400.00 on the tips so I do not want to damage them.

Bill

[Joe L.]

Re: 70 exhaust mis-fit, L46 4 spd.

Hi Joe,

Me too. However, the extra length does not allow for the tip to go on far enough and because of the bend it starts to twist a little so it does not come out straight.

I was told the tip should only stick out about 1/2"-3/4" past the opening. I can get it to about 1" before it starts to twist. Since the other side is so much shorter it wants to be sticking out about 1/2". I might be able to compromise at 3/4" but it looks like the driver's side starts to twist so the tips are crooked.



If I did not have to tap the passenger side tip to get in on far enough I would not be so concerned. I spent $400.00 on the tips so I do not want to damage them.

Bill

Bill-----


If the tip starts to "twist" before it gets to the correct, "fully seated" position, it sounds to me like the angle of the welded-onto-muffler extension pipe is not right OR the muffler is not at the correct angle due either to a problem with the exhaust pipes or mis-adjustment at the hanger bracket.

[Scott K.]

Re: 70 exhaust mis-fit, L46 4 spd.

Hi Joe,

Me too. However, the extra length does not allow for the tip to go on far enough and because of the bend it starts to twist a little so it does not come out straight.

I was told the tip should only stick out about 1/2"-3/4" past the opening. I can get it to about 1" before it starts to twist. Since the other side is so much shorter it wants to be sticking out about 1/2". I might be able to compromise at 3/4" but it looks like the driver's side starts to twist so the tips are crooked.

If I did not have to tap the passenger side tip to get in on far enough I would not be so concerned. I spent $400.00 on the tips so I do not want to damage them.

Bill

Hi Bill -

We'd like to help you troubleshoot your exhaust installation. Please give us a call at 800-345-4122 and ask for Dave at ext. 274. Any pictures of the install?