Again I am looking to replace my exhaust system as I know they are so important as to the proper running of the 4.5. MY QUESTION: Is the system used in the 72 300SEL the same as the one the SEL or SE 4.5?

SEL, yes. SE, no. SE is a bit shorter in the pipes from the 1st to 2nd muffler.

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k

Could I extend the pipes toward the back to match a SEL?

I suppose you COULD, but I don't know why you would, unless a certian eBay auction is eating at you

I've thought of asking for just the left header pipe, see if he could sell it seperatley, mine has a few dents in it (not of my own doing, we had a stone driveway with a steep hill at my old house)

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k

You know!! Yea, I'm thinking about picking the w hole system up because I want orginal. Figer I culd slip two joints about 8" between a cut toward the rear.

Header pipes are 4" longer on the SEL, otherwise it's identical. You could splice in an extension, but I would weld it onto the pipe rather than using a second set of clamps -- I've been told extra clamps cause troubles with this exhaust system because it is so heavy.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks for the tip Peter.

Actually the head pipes are identical. It's the resonators that are 4" different in length. You couldn't extend the rear of an SE exhaust to fit an SEL, no. The exhaust system is designed to fit a certain way. You would need to weld a piece of pipe in the pipe section of the center resonator to accommodate an SE exhaust.

This is exactly what I'm doing, replacing my old and rusted centre and rear mufflers (450 SEL) with new ones for SE which I happen to have.
My question is: Does the 4 inch extention for the pipes need to be in front of or in the back of the center muffler. I havent been under the car to measure this.

Tomi

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MB 350 SL 2.8 -72
MB E220 -95
MB 230 E -82
MB 450 SEL -80 (project)

Tomi: I don't know if anyone knows, actually. Your 450 is a 116 chassis, this is about the 280/300 4.5's (108/109 chassis). The stuff in here might not pertain to your car at all! I'm going to GUESS and say you need to add X amount directly after the exit of the center muffler. X may or may not = 4" with the 116!

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k

I only have grease under about three of my fingernails, so please bear with what may just end up being a stupid question.

This may only be moderately related to the quote above, but just wondering...........

If you obviously have exhaust problems on, say, a 75 450SE, would it be possible that an untrained ear could misconstrue this as a timing issue?

Mockles - Yes, if your exhaust is restricted YOU and others may think it is a timing issue, to much backpressure and the car will "fight" to run but will not do like it is supposed to. Restricting Power. Other things will do that also. TOSBT, aka four greese fingers.

Yes, too much backpressure will indeed do so... OR you could have an issue like me:

I have a leak between my cyl head and exhaust manifold, and the byproduct is a "Ticking" sound that makes it sound like the timing is too far advanced and the engine is pinging.

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k