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Old Sep 30, 2023 | 11:43 PM
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Default Help 1980 engine bay experts

Hello, one of the 1980 cars I am looking at is a 10/10 for body and interior. However, in the engine bay, I am wondering about the valve covers and the ground strap on the passenger side to the valve cover. ?? It looks like it has all the smog equipment. The distributor/ignition shielding is missing, and the car has side pipes. Engine bay experts, your help is appreciated. Thanks!

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Old Oct 1, 2023 | 12:21 AM
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Looks like the ground strap that should go to the ign. shielding cover that is missing.
other than that, yes they sure are ugly when box stock.
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Old Oct 1, 2023 | 12:55 AM
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The valve covers mean the heads (at least) are not original. Could be L98/ZZ4 heads (or engine), or Vortec heads. Check the engine stamp pad.
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Old Oct 1, 2023 | 03:25 AM
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Absolutely, I should have noticed that as well. Center bolt valve covers certainly don't fit stock heads. But everything else is a mess. Why would you go through the trouble of fitting better heads and leave all this stock stuff behind? Air pollution control state??
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Old Oct 1, 2023 | 05:19 AM
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Aside from originality nothing in that engine compartment would make me run away.
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Old Oct 1, 2023 | 08:09 AM
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The ground strap would normally be attached at the stock valve cover bolt at one end and the other end would attach to the black plastic (metal foil lined) ignition shield with a wingnut. It's an AM radio interference shield but you probably don't have need of that? You can see the strap in this photo below.

There is some canister over your A.I.R. pump that I do not have on my '80 below. Might be engine specific?

If you have side pipes, they must be hooked up to the factory exhaust manifolds. All the EFE and smog stuff is still in place.

This is pretty accurate. The chrome air cleaner lid is NCRS questionable as they are "supposed" to be black paint but this one might actually be original. Cant be proven.

Last edited by stingr69; Oct 1, 2023 at 09:47 AM.
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Old Oct 1, 2023 | 12:23 PM
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What's the 5th digit of the VIN, is it an "H"? From looking at the dual snorkel air cleaner and the accordion like hose entering the front of it, it looks like the air cleaner used on 80 California emission Corvette 305's. An "H" in the VIN would identify it as originally being a California 305 (an "8" would be a base Federal emission L-48 and an L would be an L-82).

The center bolt valve covers identify the heads (and likely the engine) as being 1987 or newer. The center bolt covers were used on 305's and 350's from 87 till about 2002 in an assortment of Chevrolet's, and other GM cars too. Depending on the year of the block there should be a pad on the right front, either in front of the head or I think above the right water pump bolt, with a letter code that can be used to identify the engine.

Originally Posted by stingr69

This is pretty accurate. The chrome air cleaner lid is NCRS questionable as they are "supposed" to be black paint but this one might actually be original. Cant be proven.
No 1980 Corvette came with a chrome air cleaner lid. The chrome lid was introduced in 1981, and that was the only year it was used.

The lid on that engine is an aftermarket lid, not a GM one. The GM lid had an additional raised ring (I guess for reinforcement?) stamped in it around the top of the lid, where the chrome lid pictured is smooth. If you compare it to the black lid in the OP's pictures, you'll see the raised ring I'm referring too. All GM did was take the stock 76-80 lid with the reinforcement ring, and chromed it for use on the 81 L-81 engine. No Chevrolet lid was ever stamped without the raised top ring, and no aftermarket air cleaner lid I've ever seen has the raised ring.
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Old Oct 1, 2023 | 01:26 PM
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This one was built in the last 2 weeks of the '80 model year. It's a GM lid 100%.

I do have a NCRS "correct" black lid that I purchased just in case but, it came to me with the chrome one on it 35 years ago so, it will stay.

The L-82 check digit is a "6" for 1980.
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Old Oct 1, 2023 | 02:11 PM
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This is a thread about a 1980, so I won't confuse anything by posting photos of 1981 cars. But all the ones I found online have that extra raised rib on the (chrome) air cleaner lids.

My 80 has that raised rib on the black painted air cleaner lid, just like the OP, with thick, sloppy black paint, FWIW. So I guess that's original?

As to why would anyone put later heads on the car without pulling the smog pump, etc? They probably wouldn't. I'm guessing that is a replacement engine from 1987 or later, perhaps to replace the original LG4 engine.

The engine stamp pad will tell us, if the OP gets back to us. I'm guessing it's not a Corvette engine at all, so the suffix code is likely to be found here:
https://nastyz28.com/chevy-engine-code-stampings.php

If it is a C3 engine, lots of info is here, including a VIN decoder to see if the car was originally a 305 LG4, an L48, or L82
https://corvettec3.ca/
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Old Oct 1, 2023 | 03:36 PM
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Thanks for everyone's help. I am reaching back out to seller to find out about heads, 5th digit of VIN, and few other details. All the expert's chiming in explain why I love this forum.
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Old Oct 1, 2023 | 03:39 PM
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Default great pic

Originally Posted by stingr69
The ground strap would normally be attached at the stock valve cover bolt at one end and the other end would attach to the black plastic (metal foil lined) ignition shield with a wingnut. It's an AM radio interference shield but you probably don't have need of that? You can see the strap in this photo below.

There is some canister over your A.I.R. pump that I do not have on my '80 below. Might be engine specific?

If you have side pipes, they must be hooked up to the factory exhaust manifolds. All the EFE and smog stuff is still in place.

This is pretty accurate. The chrome air cleaner lid is NCRS questionable as they are "supposed" to be black paint but this one might actually be original. Cant be proven.
great pics!
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Old Oct 1, 2023 | 04:59 PM
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Originally Posted by bhk2
Thanks for everyone's help. I am reaching back out to seller to find out about heads, 5th digit of VIN, and few other details. All the expert's chiming in explain why I love this forum.
Be sure to ask for actual pictures, not just the number. You'll want a clear picture of the engine stamp (just in front of the passenger side head at the top of the block, under the AC compressor), the VIN tag in the window (also a great indicator of rust), the #2 body mount pockets behind the kickpanels, and the body trim tag inside the driver side doorframe.

Also, clear pictures of all sides with the air cleaner assembly removed would also help. I saw no trace of the GM Corporate Blue paint that should be on the original engine (but probably not the intake), except for a hint on the engine hoist loop.

Even if you don't post them here, you'll want this information before you decide to buy a car. And if it was originally an LG4 engine that now has a ZZ4 crate engine (or some other replacement), a previous owner did you a HUGE favor.
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Old Oct 1, 2023 | 05:54 PM
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It probably doesn't matter for all practical purposes if the engine was replaced. In fact, it might be even better, depending on what it is. Unless you're going for all original.
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Old Oct 1, 2023 | 05:56 PM
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It is an 8, so that is an L-48.
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Old Oct 1, 2023 | 06:08 PM
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That VIN tag looks very clean. That's a good sign. Is this car a 4-speed? I didn't see a second dipstick.

Anyway, the car originally CAME with an L48. That does not mean that's what's in there now. Did the owner send any other pictures? Did you ask for the engine stamp pad?
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Old Oct 1, 2023 | 06:24 PM
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Default 1981 with Blueprint engine

The second car making my search list is a 1981. It is $4500 higher in price than the 1980, but has had much more work done: blueprint engine, 3:55 differential, new brakes, clutch, and other parts. Seller has swapped in C6 seats and T-10 transmission linkage that sort of spoils the look for me. Anyone with C6 seats in an C3, or experience with the Blueprint engine, or transmission?






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Old Oct 1, 2023 | 06:26 PM
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Originally Posted by Bikespace
That VIN tag looks very clean. That's a good sign. Is this car a 4-speed? I didn't see a second dipstick.

Anyway, the car originally CAME with an L48. That does not mean that's what's in there now. Did the owner send any other pictures? Did you ask for the engine stamp pad?
Yes, only owned manual trans on my corvettes. I asked if the heads and exhaust below the manifold were replaced or if it is a different engine. Still waiting for that. I have another option, an '81 that is closer to me but more $$.
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Old Oct 2, 2023 | 08:27 AM
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If you drove a Hurst equipped four speed then hopped in a stock shifter car....you would want the Hurst back.......
The Blueprint 350's are a decently built engine but I have found a huge oversight on their part as far as the intake manifold is concerned. There are a couple of people out there that have complained about leaky intakes and the problem is that this is a Vortec spec intake and the heads do not have Vortec ports......although they are drilled with both bolt patterns......the intake ports have a pretty horrible mismatch and I can't believe Blueprint ships them this way........

Jebby
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Old Oct 2, 2023 | 08:34 AM
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You should probably start a new thread for the 81. I find it odd that it has an adjustable vacuum advance, that has been capped off.
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Old Oct 2, 2023 | 03:29 PM
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The seller disclosed that the engine is from another vehicle. While I like a lot about the car, the different engine with everything else appearing to be stock is not quite what I was looking for.
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