C3 Off Road/N11 Mufflers
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| Year | Application | Header Pipe # | Secondary Pipe w/Muffler | System # | Video/Sound |
| 1968 - 1972 | 327/350 4 Speed 2" to 2½" | 323539 $119.75 |
323025 $336.00 |
323106 $459.00 |
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| 1968 - 1972 | 327/350 Auto 2" to 2½" | 323519 $119.75 |
323102 $336.00 |
323155 $459.00 |
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| 1968 | 427 4 Speed 2½" | 322409 $144.85 |
323025 $336.00 |
323191 $479.00 |
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| 1968 | 427 Auto 2½" | 323566 $144.85 |
323102 $336.00 |
323202 $479.00 |
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| By adding '-CS' to the part number, you will receive carbon steel pipes that re formed and welded as close to original as possible. The conventional part numbers are for our regular aluminized pipes. Please Note: all tubing is 14 gauge single wall pipe unless otherwise noted. | |||||
68-72 2 1/2" Clamp On Off Road Mufflers
| Year | Description | Part NO. | Price | |
| 1968 - 1972 | 2 1/2" Clamp On Off Road Muffler | 323325 | $205.00 | Detail |
N-11 Original Mufflers and Markings
The prints for the off-road muffler were drawn on February 26, 1963. The part numbers were 3845735 and 3845736, (also the numbers used for the service part version.) The final revision to the print was made in 1976, when it required that all mufflers be embossed with the part number, source, and GM trademark. The original muffler/pipe units that were shipped to St. Louis were marked by a yellow stencil which included the words "Off-Road Assembly" along with a manufacturer's code. (See enclosed view.) The N-11 option was not available in 1963, but we have elected to offer them without the stencil. They look and fit the same as the low performance mufflers, but the difference is in the sound and performance. There are some numbers and prints out there that may lead you to believe that a clamp on version of the off-road muffler was offered. A clamp on style is a great way to go when it is time for new mufflers. They maintain the stock appearance, produce the original sound and feature improved performance.
It appears the only year that the N-11 option was offered for the C3 generation was 1968. The original numbers were 3623603 and 3923604. The parts book shows the numbers 3931803 and 3931804, but seems to indicate that they are a clamp on type. The prints show them with dual mounting brackets, which mean they were useable on 1963-1972. The 1972 parts book has part # 3943385 and 3943386 listed as "off-road", but it does not include the pipes. Prints also indicate that this particular muffler was a dual bracket.
We will be offering a 1968 off-road welded pipe and muffler assembly which can be used on 1970-1972 cars.
