Stock motor
- Thread starter poppachap27
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Oh without a doubt an Olds 350 or 403 is a good upgrade. There are good mid 9's compression pistons for both. There are actually 68-69 5A Olds 350 heads for sale right now on this site. It would fool a few gockers if he puts a layer of grease over the block casting number after painting it semi gloss black like the 307. The 455 will probably not fit the stock air cleaner unless maybe the recessed Tornado iron intake is used. He could also add a 4" stroke to the 307, if he wants it to look completely stock. Thornton or stock manifolds, he could fool a lot of people, even with a 350 or 403. Or he could He could also just add glass packs if he only wants more noise and be completely legal.
The cheap way- poke a bunch of holes in the muffler
The expensive way- get new mufflers. Take it to a good exhaust shop and tell them what you want to do and they know what they can legally do and/or not do and get you the sound you want. Spend your money once. Trying to skirt regulations/laws, etc., may be way more expensive by the time you get done fighting City Hall. Even if you're right, and if they wanted to pursue it, the Feds have way more time and money to hound you and drag it out and break you financially. Choose which hill you want to die on. While 99% of the time with a car that's almost 40 years old, nobody cares.
First ask yourself, what is your goal with the car and do you ever think you'll sell it? A "chip" in these cars are virtually useless for performance. Yeah, they may advance timing a bit or other piddly stuff, but you're still OBD1 and that has limitations in itself. If your goal is to stray away from having a reasonably valuable stock H/O, then go for it. If you want to sell it later, you're not going to help retain the car's value and make it harder for someone else who wants a stock one to put it back the way it was. Pretty much anything behind the catalytic converter isn't even looked at except maybe by local law enforcement. So you can improve sound with new mufflers without much of a chance of breaking the laws for the most part.
The expensive way- get new mufflers. Take it to a good exhaust shop and tell them what you want to do and they know what they can legally do and/or not do and get you the sound you want. Spend your money once. Trying to skirt regulations/laws, etc., may be way more expensive by the time you get done fighting City Hall. Even if you're right, and if they wanted to pursue it, the Feds have way more time and money to hound you and drag it out and break you financially. Choose which hill you want to die on. While 99% of the time with a car that's almost 40 years old, nobody cares.
First ask yourself, what is your goal with the car and do you ever think you'll sell it? A "chip" in these cars are virtually useless for performance. Yeah, they may advance timing a bit or other piddly stuff, but you're still OBD1 and that has limitations in itself. If your goal is to stray away from having a reasonably valuable stock H/O, then go for it. If you want to sell it later, you're not going to help retain the car's value and make it harder for someone else who wants a stock one to put it back the way it was. Pretty much anything behind the catalytic converter isn't even looked at except maybe by local law enforcement. So you can improve sound with new mufflers without much of a chance of breaking the laws for the most part.
Always the biggest, steepest, gnarliest one. If you're gonna die, make it worth it.
Don't forget the EPA's national guidelines for cat converter removal and replacement which was issued in 1986, when G bodies were still in production. Basically you can only remove and replace a cat converter after it has failed. You can't legally remove a good working cat converter which includes removing a good single for dual cats. Furthermore the 86 guidelines state the replacement cat must match OEM specs and be installed in the stock location. The 86 guidelines are mentioned in your quoted texts. Moreover, dual cats each only get half the exhaust heat of a single cat and would not operate correctly. You would need smaller dual cats to heat them better.
GM never offered a dual exhaust system in any gas powered G body during the 80's in the US, so after 1990 its illegal to do such a swap. If GM had it would be ok. Ford offered a dual exhaust option for 2008 Crown Vics so its ok to swap out a single exhaust to dual today in that case. Furthermore, going by the 1986 guidelines, a dual exhaust is still illegal on post 86 G bodies even if the swap was performed before 90.
If the dual exhaust or test pipes are nice, clean, and shiny would be evidence that its a recent swap. If you have to put in a non stock exhaust you better age it. A dual exhaust combined with LS swap would be stronger evidence of a post 1990 install. A letter from a PO would only be proof that the current owner did not break any emission laws, but not proof that the previous owner is innocent. That is presuming you can even get a hold of the PO, or that he would be willing to help you instead of throwing you under the bus to protect his own butt. Frankly, without concrete proof the non stock exhaust was installed before 1990, you still have an uphill battle. Especially on a post 86 car. This is why its a good idea for both sellers and buyers to document everything before the sale is finalized.
My main point still stands that keeping the stock exhaust setup is alot easier than fighting a mountain of legal entanglements which is part of the law's design. It also still holds true that it is illegal to install a dual exhaust or delete the cat converter in a Gbody today.
Other thing is a business is not a court of law and is not required to presume innocence. An exhaust shop can still refuse to work on a non stock exhaust setup without proof of legality and even with it simply to avoid redtape hassle. Most will refuse to replace a working legal exhaust with an illegal one today. The EPA does send agents posing as customers to test suspect shops.
As for improving exhaust sound, just install a louder or quiter mufflers of your choice. My Ranger pickup has five cats but has a decent exhaust tone with the aftermarket high flow muffler I installed in it. The original muffler rotted out and the high flow muffler was on sale cheaper than a stock one.
From a practical standpoint, I doubt anyone in my state has ever had to "fight a mountain of legal entanglements" over removing a cat or adding dual exhaust......California is obviously on the other end of the spectrum..... How the OP decides to proceed is highly dependent on what state he lives in.
I'll ask this, why would in this day & age, how could installing a cat that matched the O.E. performance would be cleaner when there are newer cats that do a better job being used as a single or dual set up? On top of that how may old school shops are there that can even bend the proper Y-pipe needed as not all shops may have the bend cards to make even a basic section of our pipes. Or even have a tech who can free hand the bends. The newest A/G is 34 years old & not all needed parts are out there to including smog parts. I have cobbled together a smog pump set up to satisfy the visable inspection as I can't find everything for the different SBC set ups. I have true duals with dual cats for this rebuild & had it like that on the last set up. Never caught flak from any inspection station. It's hot rodding, most mods we do is "illegal" in some form somewhere. Make it safe, cleaner, better & more fun than original. Unless it's a rat rod, then just make it run.
I doubt most of the more advanced modern cats are designed to be used with carburetors or flat tappet motors. Big thing is every engine configuration since the 70's has a government certified low emission package. Either the EPA or CARB tests the vehicle to see if it meets their regulations they have set tor that year.
Legal low emission performance parts like the old TES headers were also submitted for government testing to prove that they didn't alter emissions output of the certified engine package. So these parts would also be certified with EPA and EO numbers. Keep in mind these tests cost a million dollars, requires 50k miles on the test vehicle, and locking the vehicle in a airtight chamber for 2 weeks. Pretty much out of the scope for most hotrodders. They are not simplying going to take your word.
As for your inspectors, from an enforcement standpoint they are doing a piss poor job. But you can't count on always having a lazy or dumb inspector. The emission laws I mentioned are federal, just because your state or county lets you slide for now doesn't make it legal. Only legal way to delete a cat or go dual for a G body is if you are converting the car into a race track car that will never see the streets.
As far as the availability of replacement parts or services goes, that is an appeal to emotion fallacy and besides the point. Discontinued parts and lack of knowledgeable professionals comes with the territory with any old machine. The economy including the auto industry is based on us buying new vehicles every few years, not keeping ancient clunkers running one more mile. Companies pretty much only want to support current stuff as that is where the profit margin is. Replacement parts for old machines is a dog market.
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