Man,
I wish I had asked this question a long time ago. I have the exact vibration described at 2800 RPM's and I am missing the bracket that goes from the A/C to the header. I am now going to dig through all my crap and hope I can find them and install them ASAP. Thanks for the great info FELNGR8

 

Mine were misssing from the car, and missing from the extra parts box, after I had my heads/cam work done. I've had to do the detective work to track down every brace and bolt that was factory original. The parts guy at the local Chevy dealer was no help. What makes it difficult for the owner with missing parts, and for the parts guy, is that the braces for the alternator and for the A/C compressor are shown on different drawings. And they are shown in different sections of the factory service manual


FWIW Superior Chevy still had the GM parts in stock last summer for my 94, including all the mainfold/header bolts. Nothing like new parts to clean up the installation.

 

I hope I can dig them out of my pile of parts at the house but if not this is great to know. BTW you don't have the P/Ns handy do you? As for the spacers and directions I bout one of the first sets ever sold by Stainless works so none of that was available at the time. I also was dropping in a 383 and had a defective clutch so I just never put 2 and 2 togeather untill this thread. Sure glad I decided to read it though as I am hoping this wil solve my vibration problem. It is a drone like vib at 2800 RPM that goes away by 3000 with the A/C on does this sound like the problem? Again thanks for the tip.

 

I had the brace from the alternator but not the two braces from the ac support casting. In this state I still got a vibration so bad I wouldn't use the A/C while cruising. I think it came in around 2700 rpm.

The braces for the A/C are part numbers 10105400 and 10128423. The part number for the manifold/header stud ext bolt is 12550726. My total order was less than 20 bucks.

Here is a picture that shows all three braces that go down to the headers. I did not install the bolt that goes onto the pipe at number 1 cylinder. NCRS will ban me from all concours shows for this oversight, shame on me. The new bolt is holding the braces from the ac by # 2.

Picture hereAC braces

You should be able to save the jpeg to see it at full size.

 

You need a spacer:


Only pic I have of the spacer

Then ground down the back of the brackets with a bench grinder.

 

Thanks a bunch, just got home and I have both braces so all I need is a bolt and spacer. I will probably just pick up a stainless bolt localy and fab the spacer. Again thanks for all th egreat info and i bet this solves the problem.

 

Thanks for the pictures guys. I just became unstuck and had a good night in the garage. Soon I'll have to get my order in with Alvin.

 

I placed my order over the phone. I never saw the web site till after hearing about it on this forum.(Like I said I win the dumba** of the year award) I would like to thank everyone for their responses. I'm still having problems with the ac bracket install, but I think I'm going to go with the stainless rod and nut idea as posted earlier. This one header pipe is so close to the bolt hole, that with a theaded rod in the hole I have just 1/16 of an inch clearance between the rod and the pipe! I'm considering making a SLIGHT indention in the side of the pipe to gain more clearance. What do you think?

 

Ok after tearing up the shop I found two of the three brackets and have one of them installed. I have the one that goes from he Alt. To the #2 header bolt but cant figure out how to install it. Am I missing somthing. My headers look just like the pic above by VictorRussell'92 and as you can see the #1 tube will not allow a spacer like the one used on the #3 tube and the bracket won't reach without it. Am I installing it wrong or do I posibly have the wrong bracet? It will fit perfect about 1 1/16 out just like the other one but there is no way to get a bolt that long in there. Any help would be great. Just to make things a little more complicated I found another bracket I have no idea what it is for. Here are the two brackets I have left. The one oon the right is the one I think goes from the Alt to the #2 header bolt (Let me know if I am wrong, the other I dont have a clue about.

 

That V shaped one I do not recognize. My '95 never had anything resembling that on it. Are you sure that's from your '94?

 

The one on the right is for the alt. The other one looks like what the two AC braces would effectively be when bolted to the AC and the header. I bought two distinct braces for that purpose, but I wonder if an earlier model C4 used something like that left one?

 

I had three braces on my 95!

I ditched the first brace and used the two braces that are located further back on the head w/o vibration.


Here's a view of my two remaining brackets from the AC end of the brackets


Look to the left of the air fitting and you can see the stud, spacer and two brackets





I believe the that ceramic coating has been holding up quite well these pics were taken this weekend; and this is my daily through the rain and snow driver.


Mike

 

No I am defiantly not sure. I have had so many projects over the past several years it could be form one of many motor/cars. I suspect it is from the 95 F-body I got my 84's LT1 from. FELNGR8 gave me some great info and pics and I am now sure I need to order the other A/C bracket. Once I get that installed I will see where I am at and possibly give stainless a cal to see if they have any suggestions on what to do about the old design and the alt Bracket. As I said before I have one of the first sets ever made for the C4 before they stopped making them for a while. I think one of the things they changed may have been the position of the pipe by the #2 hole. BTW Thanks to everyone it has been a huge help

 

I just had the same problem on my 93. That y shaped bracket must be from another year. If you are looking from the drivers side 1 bracket goes from the lower right compressor bolt to the third header bolt. I used a spacer and the regular exhaust manifold bolt. The other bracket requires the removal of the compressor and there is a threaded hole under the alternator. Other end goes to the same exhaust manifold bolt.

Fred

 

92 here. I've never seen the bracket on the left. I've always had the normal 3 brackets and I cannot fit the single one off the #1 bolt.

 

i received my set yesterday.i have not started installing them yet,but i did notice two spacers wired to the header flanges when i opened the box..

 

On my '95, there's a bracket that goes from #2 bolt (behind the #1 pipe) to the rear of the alternator. If that's the one you're speaking of, it's not needed. Just be sure and put some washers or a spacer between the rear of the alt. and the rear alt. bracket to take up the space where this support would have gone.

 

My hat is off to you guys who can do this yourself. I have neither the garage space or the time. The Vette is my only car and a dd and so I paid handsomly to have my local vette specialty shop do the install along with replacing a leaking tail shaft seal and some other routine maint.

Perhaps I am stupid also but for the $ we all paid I feel that it was unacceptable not to have a printed out direction sheet included in with the parts. I ordered the cats & entention pipes and for all the bungs to be welded in as I have to have the car smog tested ever two years.

You might notice in pics by others that there is a weld between the primaries and the outside of the flange. On my set, the pipes are only welded to the inner face of the flange. I called SW and was told that this is how they always do it and that a weld (for strength) to the outside face of the flange is not needed.

My "parts" all came packaged in a nice plastic bag that included spacers for the alternator and cut pieces of tubing for both the compressor brackets and the dipstick on the other side however the shop had several issues with one of the pipes on the passenger side interfearing with the bolts and also had to do a bit of fabrication.

This 1st group of shots is all from the drivers side. I wonder if what we were all seeing as a "Y" bracket is actually 2 brackets laid side by side. These two bolt to either side of the compressor and then meet at the outside of the extention tube on the driver side. The 3rd bracket which is from the alternator is no longer used (as the Kid said) and you can see that there are now 3 spacers on the alternator bracket in its place.

The first & 3rd pic show the spacer and the 3rd clearly shows you the two brackets bolted together. The 2nd & 4th pic show the 3 spacers behind the alternator.

You might notice that the pipes are already turning color and I am a bit disappointed that its happening so soon. I've put about 100 miles on the car since I picked it up last night consisting of 3 heat and complete cool down sessions. I'll post a few from the passenger side in a few minutes.

 

These pics particularly the middle one shows another piece of supplied spacer pipe is used to mount the dip stick. The fuel lines were also disassembled and shielding put around them as they were less than an inch from the pipe. Booties were also put around two of the plug wires.

Unfortunately when I went to get the car last night I didn't have my camera with me and thus I have no shots from the underside to show you the beautiful job the shop did mating up the cats & pipes up to the resonator. An extention harness was required for the 02 sensor wires and shielding was also put around the cable on the drivers side of the tranny pan.

I agree with Slalom4me, I bought these because they were the only ones that come with 1 5/8 primaries. The car sounds nice .... not louder but deeper .... and from my sensitive butt I would say that it feels like a 20 - 25 HP gain and quite a bit more low end - mid range torqe.

 

Send Scott an e-mail. Mine came in a seperate shipment