I need to replace my inner and outer rocker panels. What runs inside the rocker panel channel that I might ruin with a plasma cutter?

Inside the long is the heater tube.
I think the tube is made of flammable materials.

Jim

Tube is made of paper.

Slow and steady wins the race.

Bad idea since you can't get inside to douse the burning heater muffler. They're NLA and not available aftermarket.

Cut or drill ...

Don't forget that the long provides the primary connection between the front and back of the car. If you cut it out, the car will get very floppy. Not to mention that the existing metal can warp from the heat of welding. Door braces are mandatory for that level of work.

--DD

You will heat the metal too high with a plasma cutter. Its thin anyway and heat is not your 914s friend.

Use a 3 inch cut off blade near the mufflers so you can control the depth of the cut.

Can also take a hacksaw blade and snap it off at 2-1/2 inches long and put it in a body saw. Put the blade in a vice and roll it over until it snaps off. At 2-1/2 inches the blade plunge will only be just under 1/2 inch on most air saws.

Forget body saw blades for anything, they suck, are not cost effective and defang too quickly. One hacksaw blade is pennys versus body saw replacement and they last much longer.

I butchered a muffler and ended up fixing it with fiberglass. Hopefully the photo will help you make your cuts.

Not that people get into their longs to replace these often, but I am surprised nobody makes one aftermarket.

I can only assume these 40+ year old heater mufflers have a good stink to them. Can something like a motorcycle muffler be adapted? Or just run a straight pipe?

i've wondered this before as well. why the paper tube? why not modify or change it while you are in there?

Industrial air compressors use something similar to silence the intake air to reduce noise. I have opened a few stacks in my life and the cartridge is not much different.
Might be able to find one that could be adapted. Not sure is worth the time and I don't think the 914 silencer actually does much.

I agree that it probably doesn't do much. Seems like if I ever have my rockers open I would then take that paper muffler out and put in straight pipe. Maybe wrap it with header tape/wrap or something.

Otherwise, a motorcycle muffler...but maybe those would apply to much backpressure against the air (that is supposed to warm your tuckus in the cabin)? Essentially, you would get little or no air flowing through the motorcycle muffler especially without the auxilliary blower engaged.