68 N11 exhaust

[Steve B.]

I have an N11 exhaust part # 736/736 with one muffler part #737 and the other with a GM stamp and other #s that I am not sure of. It is a welded system and the pipes are squarish shaped. The mufflers have two mounting brackets on them not one which I thought would make it correct for a 68 N11 car. I mentioned this to someone and he told me that 68 N11 had pipes that were more of an oval shape so I am confused as to whether it is correct for a 68 or just 65/7. Thanks in advance

[Joe L.]

Re: 68 N11 exhaust

Steve-----

The pipes used for the 65-67 and 68 N-11 systems were the same. The only difference between the 65-67 and 68 N-11 system was the rear muffler brackets. The 65-67 N-11 system used a bracket for the mid-year style muffler mounting; the 68 system used a bracket for the C3 style mounting. The 68 muffler/pipe assemblies were discontinued many years ago; the 65-67 assemblies were still available until the more recent past.

I do not know how the "dual bracket" muffler/pipe assemblies that you have "figure into the picture". I have never seen an N-11 system with "dual brackets" although the last available standard system mufflers for 2-1/2" exhaust did have dual brackets.

With dual brackets the N-11 muffler/pipe assemblies would be SERVICE for all 65-68 Corvettes. However, as I say, GM never catalogued the same part number for all 65-68 assemblies. The 65-67 and 68 had different sets of part numbers, solely because of the brackets. Do the parts that you are speaking of have any PARTS TAGS with GM SERVICE part numbers on them?

[Steve B.]

Re: 68 N11 exhaust

Joe,
The pipes do not have the tags on them but I just installed an NOS 67 N11 exhaust on one of my cars. Those pipes did have the tags with part #s 735 and 736 respectively as the last three digits. This exhaust is identical save for the dual mounting brackets on the mufflers. Have you ever heard of the oval shaped pipes for 68N11s that was mentioned to me?

[steve wallach]

Re: 68 N11 exhaust

The 68 pipes are "flattened" as they run under the car approaching the mufflers. They are therefore "oval". I have never seen "square" pipes for 67s or 68s?

Regards,

Steve