lg4vette

Hello. Excellent information available here. Thanks! I have a general question about our '80 H code (LG4-305). We're in Michigan and I am trying to decide if I should try and :
1) find a replacement 305 engine with related emissions
2) purchase a used 80 L48/L82 with emissions
3) or use the existing partially-installed 350CID and try to locate required emissions equipment.

In this state there is currently no emissions testing, so the car would be legal for the moment, however I don't want to scramble later when the inevitable happens and testing is begun here in MI.
I'm not interested in running blistering times at the strip, and originality is of somewhat importance, however I'm not able to find any vette LG4's out there for sale. What is your input concerning this? The current 350 may be usable if I could get the emissions equip, but I'm unsure if the accessory holes would mate up properly as vettes seem to use some particular brackets and such.
What's your opinion?

Michel B

I believe it all depends on the year of the 350, also the year of the heads. Small blocks should have the same holes. blocks older than 1977 are not compatible with modern (hole wise) accessories. Now I think I'm on the right track but ohters will most likly help out on this....

Kalway

You can put a 350 in there and use the majority of the emissions controls on it. The rule of engine changes is the newer of the two parts (car or engine) has to meet the newer of the two for smog. Then for engine changing of size, if a model was offered with a 5.0 and 5.7L that year you can change between those two sizes without having to get it recertified.

If they aren't doing smog tests in Michigan now, I'd not worry about it because the furthest they'll go back, if they reinstate smog testing, is like 20 years.

Minnesota had smog testing, but got rid of it because it cost more than it was worth.

Russ Bellinis

I don't think you'll have any problems either way. I doubt if anyone will even notice if it has a 305 or a 350. The main thing is to have all of the smog equipment to install if you need to.

PROSOUTH

The smog sticker from the 305 may need to either disapear or be changed to a 350 sticker. If you can't find one I have a new one to go under the back of the hood for a 350 CI '80 Corvette still in the wrapper for $10 shipped. jim

page62

Is there even so much as a rumor of smog testing in MI? Given the current political climate, it seems that testing is on the wane in most places, except Kalifornia...

Also, if MI has antique license plates available, you may be able to use them to be exempt from future smog testing.

lg4vette

Thank you all for the replies. This forum is fantastic.
To utilize a 350 then, what emissions equipment would I need to get ahold of, and what year(s) block/equipment would you suggest?
I was thinking, if possible, of using a GM replacement 350 crate engine with the 260HP rating and 3-year warranty. If I was to purchase accessories such as alternator bracket/alternator, water pump, A/C equipment, exhaust, etc. for an '80, would/should it be compatible with this engine and the 80's engine compartment?
The transmission is currently a TH350, but not from a vette, if this matters. I was thinking of possibly having the current 350 rebuilt as it's not completely installed, however I have no idea what it's from nor what accessories/emissions equip. would fit.

Thanks again for all your help in this.

lg4vette

I keep hearing in the car magazines that "if emissions laws aren't in your area soon, they will be". I just assumed they knew what they were talking about, as I certainly don't. Maybe I'm not listening to the proper sources...

lg4vette

Any thoughts on what I was considering (engine wise) in a previous post in relation to the GM 350 (260hp)? Thanks.

fauxrs2

I would say more testing is much more likely than less..nationwide..

The 350 replacement motor is a fine start - i do believe that is a vortech headed motor. since your car was originally a CA car and if you are really interested in setting the emissions gear back in there then you are looking at...

AIR (Air injection reactor) : these are the pipes that go into your exhaust manifold - they connect to the ubiquitus smog pump

EFE (Early fuel evaporation): this is the little butterfly in the passenger side exhaust that forces exhaust through the crossover in the ngine until the engine is warmed up

PCV (Positive Crankcase ventilation): the little check valve in teh drivers side valve cover that connects to the carb

Catalytic convertor:

Thermac: this is the air cleaner with the vacuum controlled doors on the snorkles (also designed to help speed up warmup)

EGR (Exhaust gas recirculation): the device mounted to the intake that dilutes your a/f mixture with exhaust gasses at certain rpm/vacuum levels ( this might be a problem with the vortech heads as i dont think they have heat crossovers - but im not sure about that - if they do you will almost certainly have to get a manifold that accomodates the EGR valve.)

thats all that comes to mind...there is probably more.

Good luck

page62

Take the LG4 and all the smog stuff and stick it in a corner of your garage. If emissions come to haunt you one day, the stuff will be there.

Now that the engine compartment is empty...go have some fun!!! All the stuff that's currently bolted to the front of the LG4 (alternator, water pump, PS pump, A/C compressor, etc.) will fit on the replacement engine. That's the beauty of small block Chevys. However, you'll likely need an intake manifold, carb, and distributor.

Even if your area DOES eventually get emissions testing, it's likely your car will be exempt. And you have an "escape hatch" if they do decide to go after you, too.

lg4vette

Therein lies the trouble...I don't have the LG4 to put in the garage. There's a 350 in the engine bay (barely) and I'm trying to figure out what route to take, go with a 350 and worry about emissions knocking on the door in the future, or find use a 305 with the emissions in tact to start with. I like the idea of keeping the vette "original" with the 305 albeit a NOM, but I don't know what year(s) would be useable.
Thanks again for the help.

Chopper Larry

I'd get the 350 and never look back or forward to worry about emissions....sell it in Texas or Arkansas then.

lg4vette

Well, the mass has spoken. Now, where would I get the brackets that will fit the 'vette engine compartment?