Question: '77 Exhaust Conversion

[JAD77]

I am finally putting my 77 back together and have purchased a dual exhaust system from Corvette Central. The system came with no instructions so it's hard to tell what pipe goes where. Since the original system had a "Y" pipe, I'm not sure where the dual hangers go on the frame. Also, I am installing the system with the body off the frame so it's a little difficult to tell if the mufflers are in the correct location. Someone from another forum was nice enough to upload a couple of pictures bu it was still difficult to see the layout. For some reason, when i put the hangers where his photo indicated, the middle interim pipe seemed to be too short by a coulpe of inches. The system was listed as a '74 exhaust system for manual tranny with 2 1/2" pipes, but a newer catalog lists the same product number for a '77 so I am guessing that there is no differece. Any help would be very much appreciated. I expected that this wold be a slam-dunk, especially with the body off but who'd a thunk? Thx, J

 

[6880 Mike]

My advice is to purchase the 74 assembly instruction manual (AIM). The 74 AIM shows the factory installation of the dual exhaust. It will also show additional hardware/hangers you might need on your 77.

 

[Dad]

Interesting, you would think that an exhaust installation would be fairly simple and well documented from the vendor. As I get the '72 out on the road more I wanted to update to the N11 type mufflers and new pipes. In all I tried 4 vendors in the last month with very little help and lots of time on the phone listing to the messages of how "important" my call was.

Today I tried one and was treated like he knew me and within 10 minutes my system was on the road to me. He ask for information that I knew he needed to get the system right from the start. He also ask if the bracket to mount the pipes by the cross member was correct for the new sized pipes and gave me a deal on it as mine was missing. I had planned to get it anyway but he was on top of his game from the time he picked up the phone until the order was done.

One vendor gave me poor information, another had little or no information available on their site, another is still a no reply, and one of those gave me over a month lead time.

Will up date this as I get the system and install it for proof of what I think is real customer service. Sadly he is not one of our vendor sponsors and he specializes in Corvettes. I had installed one of their chamberd systems before and loved the sound and quality.

System got here before they were added to my credit card. Took longer to remove the old system than it did to install the new, fit was excellent. Sound of the off road is aggressive but no drone. Packaged as left side and right side with all parts needed to install.

 

[JAD77]

Thanks guys. I think that I have it largely figured out. I will hang the system the way I think it's got to go then make adjustments after the body gets put back on. However, it would seem that the vendors would at least provide some simple diagram to identify right and left pipes along with hanger locations. VB&P provides little instruction diagrams with all of their suspension components, these other vendors should do the same IMHO. j

 

[6880 Mike]

The dual exhaust cars have a hanger for both pipes on the tranny crossmember which is probably not on the catcon cars. 74 AIM will show it and give you a GM part number.

 

[JAD77]

The dual exhaust cars have a hanger for both pipes on the tranny crossmember which is probably not on the catcon cars. 74 AIM will show it and give you a GM part number.

Thanks Mike. I purchased the dual hanger when i bought the system. I think I've got the right pipes in the right places now, just need to put the body back for final tweaking before torqueing things down. j