'79 with new Crate 350 HO engine
Thread Starter
Navigator
Joined: Jul 2007
Posts: 9
Likes: 0
'79 with new Crate 350 HO engine
Hello everyone! Here is to my first post!
So, I have decided to un-mothball my 79 'vette that has been sitting in the garage for about 10 years
I live in oregon and it currently is NOT street legal as It needs to have Catylitic converter and be measured for emissions < 1% co and <220 hydrocarbons.
I have decided to have the TH350 tranny fully re-built and beefed up a bit for the 330hp that the new crate engine puts out (I am buying the 'deluxe' close-to-turnkey engine).
OK, so my question. I would like to put headers on and have that go into a 3" CAT then go out to seperate flowmasters. What are my chances of measuring below the above numbers at DEQ?? Would I be better off with dual exhast and two seperate cats? If I go that route will I have to get a new cross member?
HELP!
thanks
Mark in Beaverton, Or
So, I have decided to un-mothball my 79 'vette that has been sitting in the garage for about 10 years
I live in oregon and it currently is NOT street legal as It needs to have Catylitic converter and be measured for emissions < 1% co and <220 hydrocarbons.I have decided to have the TH350 tranny fully re-built and beefed up a bit for the 330hp that the new crate engine puts out (I am buying the 'deluxe' close-to-turnkey engine).
OK, so my question. I would like to put headers on and have that go into a 3" CAT then go out to seperate flowmasters. What are my chances of measuring below the above numbers at DEQ?? Would I be better off with dual exhast and two seperate cats? If I go that route will I have to get a new cross member?
HELP!
thanks
Mark in Beaverton, Or
Melting Slicks
Joined: Apr 2002
Posts: 2,337
Likes: 14
From: Norfolk VA
No you will not need a new crossmember to have a true dual exhaust. The crossmember already has two holes to run true duals. Sounds like your state has emissions inspections. If you choose to have a true dual exhaust you will need two cats. If your state has a visual inspection also they will look for the other smog equipment (air pump, dirverter valve, etc.) in addition to the sniffer. I personally think 3" pipes is overkill but if that is your wish go for it. My 79 had true dual exhaust with no cats when I bough it. I lived in northern VA than and they have emissions inspections and my vehicle passed the test with the cats installed. Can't say for sure if you will pass or not.
Last edited by Oldguard 7; Jul 14, 2007 at 03:10 AM.
Race Director
Joined: Jan 2003
Posts: 15,176
Likes: 88
From: State of Confusion
I bought a brand-new 1979 Z28 in October of '78, and in '81, we ripped-out all the emission stuff, and added a hotter camshaft, small-chambered heads, aluminum intake, Holley 650 carb, headers, etc.:
Taxylvania instituted a sniffer-test (no visual inspection for all OEM parts ), so leaning-out the carb brought the motor back-into 1979-pecs, and once it passed the test, we fattened-her back-up while still-on the machine until next year.
I'd assume that your car will need to meet '79 regs, and if you don't need to pass a visual-inspection, I'd think your car, too, would pass.
Hope this helps, and welcome to the Forum!
Taxylvania instituted a sniffer-test (no visual inspection for all OEM parts ), so leaning-out the carb brought the motor back-into 1979-pecs, and once it passed the test, we fattened-her back-up while still-on the machine until next year.
I'd assume that your car will need to meet '79 regs, and if you don't need to pass a visual-inspection, I'd think your car, too, would pass.
Hope this helps, and welcome to the Forum!
Racer
Joined: Feb 2006
Posts: 324
Likes: 0
From: South Elgin IL
If there is a visual inspection, you may need to verify what that is. In some states, a visual means the system can't be altered. Since the 79 came with a single cat, a true dual/dual cat would not pass the visual in that case because the car was altered from factory specs.
Safety Car
Joined: Oct 2004
Posts: 3,725
Likes: 5
From: Minnesota
I have that engine (non deluxe version) and really like it. My only comment is that you may want to reconsider throwing money at the old TH350 and put that towards an overdrive 700R4 or 2004R. Lots of threads on this. It takes a little time and maybe a bit more money than rebuilding the TH350 but it's well worth it IMO. My wife and I just got back from a 1500 mile road trip with my 75 with a 700R4. Without the overdrive cruising the interstate at 80 mph plus wouldn't have been so enjoyable. Better gas mileage is another plus.
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
A modern 3" cat will work better than any 79 cat ever made so no problems there. Since you are running a single 3" cat might as well skip the headers, will not provide much more than the old ram's horns and will make install much easier.
Melting Slicks
Joined: Oct 2005
Posts: 2,526
Likes: 99
From: Apache Junction, Arizona
St. Jude Donor '12-'13-'14-'15-'16
I have a 79 with dual 2.5" cats and mufflers. Engine is a highly modified 350. The car passed all smog test here in IL. I replaced the exhaust last month and installed Hooker Sidemount Hedders since I registered the car as an Antique Veh. with the state.
It now runs MUCH STRONGER, and COOLER.
Why don't you check with your State Laws and see if there are any exceptions to Antique Veh. and if there are do what you want.
It now runs MUCH STRONGER, and COOLER.
Why don't you check with your State Laws and see if there are any exceptions to Antique Veh. and if there are do what you want.
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Thread Starter
Navigator
Joined: Jul 2007
Posts: 9
Likes: 0
Good advice guys, keep it coming.
Here on Oregon they do NOT look under the hood - so no need for all the smog junk in the engine compartment. It looks like the law in oregon is that anything 1975 and newer MUST have catalytic converters, be measured at the tailpipe and for db level below 93.
Took the brake calipers off today - they are leaking and I have decided to just purchase new ones. Any advice as to what to get and where to get them?
Any advice on a good set of headers?
Hey, my wife was even out in garage 'prettying up' the Corvette polishing the tail light lenses with Flits plastic polis (made them look like new).
thanks all!
Here on Oregon they do NOT look under the hood - so no need for all the smog junk in the engine compartment. It looks like the law in oregon is that anything 1975 and newer MUST have catalytic converters, be measured at the tailpipe and for db level below 93.
Took the brake calipers off today - they are leaking and I have decided to just purchase new ones. Any advice as to what to get and where to get them?
Any advice on a good set of headers?
Hey, my wife was even out in garage 'prettying up' the Corvette polishing the tail light lenses with Flits plastic polis (made them look like new).
thanks all!
Melting Slicks
Joined: Apr 2002
Posts: 2,337
Likes: 14
From: Norfolk VA
If you wish to replace the calipers, there are many different vendors who sell the stock c-3 calipers, new or rebuilt. Since you are replacing them there are also a ton of vendors that sell aftermarket calipers which are lighter than stock and you can upgrade as much as your pocketbook will allow. Headers also vary, most use heddman, hooker, or dynomax of the ceramic coated variety. I'm going to purchase some Sanderson headers, pricey but very good quality and extra thick flanges. Btw welcome to the forum
Le Mans Master
Joined: Oct 2005
Posts: 6,247
Likes: 471
From: Glen Allen, VA
On the calipers, make sure whatever you get has stainless steel sleeves. I went with the original style lip seal calipers on mine, but a lot of people will say to go only with O ring calipers. I know here in VA, if your car came with only 1 cat, you can't install 2. Fortunately mine is old enough to be registered as an antique so I don't have to worry about inspections.
Melting Slicks
Joined: Apr 2004
Posts: 2,008
Likes: 38
From: Space Coast Gator Territory
I have that engine (non deluxe version) and really like it. My only comment is that you may want to reconsider throwing money at the old TH350 and put that towards an overdrive 700R4 or 2004R. Lots of threads on this. It takes a little time and maybe a bit more money than rebuilding the TH350 but it's well worth it IMO. My wife and I just got back from a 1500 mile road trip with my 75 with a 700R4. Without the overdrive cruising the interstate at 80 mph plus wouldn't have been so enjoyable. Better gas mileage is another plus.
