"Fender well Headers" I had them on a high rider "gasser" 56 chevy I built in in the 70's.

I did more investigation on the length of the exhaust system in order to understand the difference between the two sides.

I measured the overall length of both sides. Passenger side is 52 7/8 and driver side is 52 1/4, so the passenger side is 5/8 inches longer. This does not explain the difference in proximity to the rear tire (passenger side is 1 3/4 closer).

The passenger side cylinder head is 1 inch forward as compared to the driver side. This is the connecting rod offset.

The passenger side pipes exit the body of the car 20 inches behind the center of the front wheel. The driver side pipes exit the body 19 inches behind the center of the front wheel. This means that the primary headers on the passenger side have a 2 inch aftward bias built in as compared to the driver side.

The aftward bias on the passenger side of the primaries explains 1 inch of the difference in proximity to the rear wheel. That leaves 3/4 inches to be explained. On my car, the exhaust exit (past the baffle) is 1/2 longer on the passenger side as compared to the driver side, leaving only 1/4 inch difference. This 1/4 inch is probably within my measurement error.

So, to get the pipes perfectly symmetrical, one would have to remake the primaries to move the passenger side exit forward by an inch, and then shorten the exit section on the passenger side by 1/2 inch.

Remaking the primaries on one side is too much trouble to me, and the offset in them may be there for a reason. This extra inch could also be taken out the of length ahead of the collector. If I were having new side pipes made, I would just make sure the exit section is the same on both sides and call it good.

Thanks RockBit, this is great information. Georgie from GasN Pipes is watching this thread and your information should help immensely creating an alternative source for ERA side pipes since Stainless Specialties is now out of business. My new pipes should be ready by February and I will post side by side pictures(SS/GasN) and then pictures of the new pipes installed on the car.

One thing I noticed in the photo of RockBit's pipes (post #18) is the spacing between the pipes on the collector. If you look at Patrick's and my photos, the pipes are tightly grouped together. Also, since my baffles are longer and presumably quiet pipes, but are actually pretty loud, it sounds like Stainless Specialties made changes over time.

The individual pipes should be grouped tightly together. The gaps between mine are my main complaint about them.

I’m anxious to see how the GasN pipes turn out.

I am too.

The pipes are the same length. The noted difference is because the passenger side cylinder bank / head is offset the thickness of a connecting rod to the rear.

Any differences in the exhaust ports from one side of the block to the other, wouldn't that be accounted for and taken out of the equation by the bends of the header tubes? The exit hole in the body is in the same absolute position from one side of the car to the other, no?

You'd think so. It's not like the side pipes aren't custom made for each side of the car. Right? When was the last time somebody said "hmmm, I wonder which side of the car these pipes go on?":cool:

I did try that but burned my ear on the side pipe:JEKYLHYDE

Very definitive statements. You do realize we are talking about an ERA with an FE, right?

On my ERA, the body cutout on the passenger side is 1/2 inch aft as compared to the drivers side. Who knew?

Many (20?) years ago we shifted the primary pipe position on the driver's side forward to clear our footbox - which we had extended for more leg room.

On our very early kits we used primary pipes that were (theoretically) replacement for the Shelby factory Comp pipes.

The Stainless Specialties mufflers can be mounted to two directions. Since I was losing my hearing, I mounted them with the internal scoops facing forward. Now I can actually talk to my passenger and my ears are improving. The opposite way is much louder.

I've had two sets of sidepipes from Stainless Specialty and neither set had the internal scoops. There were just holes drilled through the the inner wall. The first set was what I received from ERA when I first bought the car back in 2002. The second was after I sent them back to Stainless Specialty around 2012 to have the muffler portion cut out and replaced.

Chris

Maybe Georgie at GasN can take some pictures when they’re building my side pipes in January and post them. It would be interesting to see how they are made. He’s also cutting open my drivers side Stainless Specialties pipe to fix a rattle, presumably the baffle came loose. I’ll sell those after installing his new pipes if anyone is interested.

Any update on this? I'm curious about the GasN pipes on an ERA.

Georgie can not get the bent 2” pipe going from the header to collector needed to build my new pipes due to COVID-19. He’s installing new mufflers into my rattling SS pipes to get me by until he can build me a new set of his pipes. Getting my old pipes back in 2 weeks.

My pipes from GasN are at the polishers. I should have an update/pictures as soon as I receive them.