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Hi,
First off I’m a newbie. I’m working on a 72 350 auto that needs a new exhaust. A local guy has a 73 small block he is parting out - all new parts he is selling - would this exhaust work for me? He would give me a decent price. Thanks so much!
Possibly… Here’s a good thread. Look at post #4. https://www.corvetteforum.com/forums...all-years.html
Also, I searched the offerings of various vendors and many list various exhaust as fitting 1968-1973, but again, I would refer to post #4 in that thread.
'72 and '73 are the same as long as both cars have the same transmissions. A 4-speed's front pipes won't fit an automatic. Look up what's offered at Zip or CC for any differences.
Should be the same except for the mufflers and exhaust tips. On 70-72 the exhaust exits on the outer edge of the exhaust tips. On the 73 they exit in the center of the exhaust tips. Thus the pipe exiting the mufflers exit at different angles. If originality is not important then they are basically interchangeable.
As mentioned by others, as long as the system from the 73 is for an automatic, everything but the mufflers are the same as the 72 system.
The front pipes (pipes at the manifolds) and secondary pipes (the pipes from the front pipes to the muffles) are the same for all 68-74 automatic small blocks, making them interchangeable. The 73 mufflers, muffler hangers and tips are all one year only parts because of where the exhaust exits from the muffler as explained above. The center exhaust hanger at the transmission crossmember is also the same for all 68-74's with an automatic trans. It's possible that the mufflers might even work if you used the 73 tips and muffler hangers, I don't know if anyone has ever tried to use them?
I don't know of any reason why you couldn't use a 68-74 manual trans system on an automatic car. As long as you used a manual trans center exhaust hanger it should all bolt up. The issue is it would sure make things a lot more difficult to remove and work on if you ever need to drop the trans to repair it.
The reason the manual transmission system will not work with a automatic is simple.
It will not fit.
A automatic system would have heaps of room with a manual.
Not so much the other way around.
…and don’t forget the pipe diameter. Base engine used 2” while the optional engines used 2 1/2” pipes. And the header pipe were different between small block and big block.
The car I’m working on is a 72 with a 350- air, power steering - would it possibly be a 2.5 inch? How can I tell without taking off the existing exhaust? Thanks so much?
Check the VIN. The fifth digit tells you what engine came in the car. A “K” indicates the base engine. “L” is LT1, “W” is LS5. This only applies if you still have the original engine.
The car I’m working on is a 72 with a 350- air, power steering - would it possibly be a 2.5 inch? How can I tell without taking off the existing exhaust? Thanks so much?
The '72 350 motor with AC and PS runs 2" exhaust. I grabbed a couple of measurements off of straight sections from both LH and RH sides of my exhaust and they measure: 2.0130" ; 2.0075" ; 2.0080" ; 2.0200" (O.D) or a average of 2.0120" O.D. for my small sample size. I have the same motor and options and mine is a 4-speed.
Last edited by KS69Coupe; Aug 14, 2025 at 02:12 PM.
Reason: added O.D. to clarify my measurements
Ok that makes sense. That brings me to this question - is it worth it to buy some exhaust “pipes” from this guy if I need to buy a new 2.5 inch manifold and a new muffler? Or better to just get it all at once instead of piecing it all together? What price would be reasonable? He’s got a complete exhaust for a 73 but sounds like the muffler and manifold wouldn’t work for me. Thanks so much!
If I am understanding thread properly, then I *think* you're saying it is a 2.5" system and he's offering the Downpipes, the Intermediate Pipes, and the Mufflers?
You have an Automatic and the is offering an exhaust from an Automatic?.
Originally Posted by Pbpabs
Ok that makes sense. That brings me to this question - is it worth it to buy some exhaust “pipes” from this guy if I need to buy a new 2.5 inch manifold and a new muffler? Or better to just get it all at once instead of piecing it all together? What price would be reasonable? He’s got a complete exhaust for a 73 but sounds like the muffler and manifold wouldn’t work for me. Thanks so much!
Ok that makes sense. That brings me to this question - is it worth it to buy some exhaust “pipes” from this guy if I need to buy a new 2.5 inch manifold and a new muffler? Or better to just get it all at once instead of piecing it all together? What price would be reasonable? He’s got a complete exhaust for a 73 but sounds like the muffler and manifold wouldn’t work for me. Thanks so much!
It's certainly up to you but I myself don't care for mix and match. Usually, just costs me more time, money, and aggravation and "patience" is not my super power. FWIW, I would at least make a call to Gardner Exhaust Systems. Not cheap but they produce absolutely perfect and I mean perfect fitting exhaust systems for Corvettes. Speak with Eric Gardner (845) 758-8003. They are a multi-generation, family-owned, Corvette specialty exhaust system manufacturer based out of Red Hook, NY. I paid $1,287.19 for mine in September 2023. My system included everything: nuts, bolts, spacers, hangers, mufflers, everything I needed to bolt on my system from exhaust manifolds to muffler hangers...they even include a spare set of clamps (a little detail that they thought of) so you could weld the mufflers to the exhaust once you have everything in place. And, my system is 100% NCRS correct. I went with steel exhaust because I am restoring an NCRS flight car. I can't over-emphasis that Gardner Exhaust Systems fit perfect.
Pbpabs
Take a look at the aluminized 2.5" system (well, mostly other than the necked-down are next to the exh manifold) from corvette central and compare the prices with what is being offered.
72 exhaust interchangeable with 73?
