Well, its time for an update:
the driver's side muffler finally went a few days ago, an inconvenient time since I was out of town on a jobsite and wife has few mechanical skills.
The back plate of the muffler rusted through and the bracket came off, so the muffler was dangling dangerously low, and looked like it might come loose. So I first wired it up again with cheap stove/hanger wire.
Problem was, the noise. The cab was incredibly loud, like riding in a deisel truck, you could hardly hear your country music over the throbbing engine roar.
The biggest problem was money. I still had the other "FloMaster" style stainless steel muffler, but obviously this car was too loud, even with a busted regular muffler and one musclecar muffler.
So I knew I had to find an ordinary muffler for the second muffler. TWO cherry bombs would be one too many for shopping at the grocery store.
I went to one metal recycler but no go. Nothing that was usable. I even hung around the metal bin dumpsters a few times hoping someone would chuck out a muffler that fell off, but nothing.
So I returned to the auto wrecker I bought the two musclecar mufflers from. After all, I paid $50 each for these babies (probably overpaid, given a new muffler is about $90) and asked a favour, if I could trade the one back for a normal muffler.
No problem. I think either he felt guilty about the price I paid for the first two mufflers, or else he just wanted goodwill and return business. He had a truckload of good used mufflers cannibalized off wrecks, and I found a suitable (slightly oversize) substitute.
I returned the second FloMaster with a tear in my eye, and headed home.
This time I was armed with a SawsAll and a FluxCore wire welder.
I cut off the hanger-wire and sawed off the muffler close to the stem at the join where it meets the pipe that turns and connects to the main exhaust.
Normally they charge an extra $50 for a muffler with this stupid bit of pipe pre-welded on so that you can connect it to the exhaust somewhere in the middle. Screw that.
I kept the pipe I previously paid for on the last (crappy) muffler that only lasted 2 years. It still looks brand new (this is how I know the muffler was crap).
All I had to do was make a new bracket to accomodate a connection to the back of the muffler at the tailpipe, and fit the other end of the muffler to the remaining pipe.
The worst part of the job was removing the bit of pipe already stuck in the 'new' muffler from where it was joined to some other car. This 3 inch piece of pipe was a real pain in the ass, and took me an hour or more of banging and finally hacking into it with the SawsAll, and prying it out with a large flathead screwdriver and hammer. (another screwdriver destroyed: cost of doing business).
Now the pipe was flared (but so what), and it fit fairly easily onto the exhaust pipe.
By the way, I had to put the muffler on BACKWARDS, to line up the holes (one end to the side, the other end in the middle): I hope this doesn't affect the performance too much, or wear.
I also scoured the rust off the muffler and spraypainted it with "Rust Converter" (see my bodywork threads) and high temperature black paint overtop. (I'm happy to report this stuff works great on exhaust systems.)
I measured the new bracket I made from a piece of sheet steel wrong, and had to re-drill a mounting hole, but that wasn't much of a big deal.
Now came the welding. On this side, I am near the gas tank spout, and also the disk brakes (the rear wheel on drivers side had to be removed to access the back of the muffler for welding). I covered the brake rotor with a plastic bag (I should have used a canvass bag or tarp).
Well this was the second time in my life I have tried to weld something, and I burned a few holes (and refilled them). I have to admit this was the worst welding job I have ever seen. I gave it a pass eventually, and put everything back together.
The car now sounds much quieter, and still has a sinister, powerful roar from the FlowMaster style muffler on the passengers side....simply awesome.
The bit of pipe left from the exhaust of the previous car (remember this muffler was put in backwards) made a fine tailpipe when sawed off with the SawsAll.
The boss thought it looked like I jammed a crowbar up the back of the car. But the muffler with homemade bracket hardly looks worse than the other muffler on the passengers side.
I can saw off the excess bracket with the sawsall later.
And the whole project here only cost the gas to drive to the wreckers (trading in the other muffler), the welding wire, and a couple hours of my time.
The Lord was with me, thanks big guy, amen.