If this has been discussed recently I apologize. Been researching/shopping later C3 asking prices (74-80) for nostalgia reasons. Had a 69 and a 71 back in the day, 1970s. Can't really afford the chrome bumper cars, hence my search range. Yes, I'm reasonably familiar with the birdcage, frame and other issues of the the C3 cars.

My question is, given two above average examples of driver quality, one with original motor and one without what is the value/price difference to the folks here?

What's my definition of above average? Non hit car, paint looks good from 2-3 feet away and has nice shine, interior has no rips/tears, all instruments work (clock excepted), a/c and heat work. Car drives out fine and had decent maintenance records. Engine bay is clean and to the casual observer (non Corvette person) appears stock. Of course clean title. These are the highlights.

I have a dollar number in mind for the difference between having the original motor or not, but have been out of the C3 game a looooooong time. Would appreciate any insight. Back in the 70s it was less of an issue, overall condition was prime, but that was before Bloomington Gold really took off and I know today is different.

 

Wouldn't that depend to some extent to exactly what not original motor is being used?

 

A really nice 383 would be worth far more than a stock L48. In these years the original engine wasn't really anything to brag about.
So, in Answer to your question. In this year group. A good non original engine is worth more than a stock L48. Especially if we're talking about a driver.

 

The one with the manual transmission will be worth more.

If they are truly identical, the NOM would be worth more to me, as it means I could restomod the car with zero guilt. I'm about to have two worthless hunks of numbers-matching iron haunting my garage for the rest of my life.

 

For a '74 to '82, I'll pay far more for a nice NOM that makes real HP vs the original fatty tumor that GM put under the hood. Although, I might make an exception for the '74 BB.

 

The bottom line is the numbers matching guys take it to the extreme. You need the correct date coded alternator case. The correct date coded starter motor. The correct markings on bolt heads, etc, etc.
none of this matters for a nice driver.
I for Instance have a original numbers matching block in my 77. But the numbers matching guys would quickly poo poo my entire car! I don't have the original heads, alternator, intake manifold, water pump, radiator, fan or fan shroud, carburetor, air filter, etc, etc, etc.
so my numbers matching block is just for me I guess.
But that block when new couldn't get the car to keep up with a Ford Pinto!
Same block, crank and rods. And Whooo Hooo I still have the original starter motor. That's about it.
But now it makes double the power that original combination made.
A lot of people really hammer these 74-82 Vettes because the power was down. But it's not hard to fix that. But then the numbers game goes out the window.
If a driver is what you want. A numbers matching car shouldn't be on your radar. If it's a museum piece your looking for. Well, that's different.

 

Interesting read and hate to rabbit trail this post so if no replies I understand.
How about the same question with color?
After reading some of these responses and i agree, i like a stock appearance for certain C3s in particular bubble back windows (i like a modded look with the sugar scoop back windows) but "numbers match" has never been that important with mid/late C3s and after reading some of these responses it changes my thoughts a bit more.

I have a no frills 1980 L48, low original miles and well documented in excellent condition white over black, I am considering changing color for my own personal taste. The paint on the car now is flawless without a single chip and done correctly fully disassembled BC/CC and polished to glass, about 10 years old but looks like it was just completed and my guess about a $10-$15k paint job 10 years ago.
I have no intentions of selling the car (but you never know) and again ive been considering a color change, im in the automotive collision and paint industry and have painted high end cars my whole life, used to teach OEM paint certification and 3 paint jobs in SEMA so it would not be a hack color change... it would be done right SEMA quality.

The job isnt a concern, I can have the car disassembled and ready frankly in several days, the same for reassembly and polish, I have full access to a $200k down draft booth at our local training center and access to the top of the line Glasurit, Spies, Sikkens, Axalta etc paint that wouldn't cost me anything.
As asked by the OP in value for non original motor how about original color, its been my only hold back is how much would I decrease the value, not a highly sought after C3 but also not easy to find like this as an 80, the color I want to change to is irrelevant but will be a stock color.
Is this a bigger deal than original motor or even less of an issue in future value if I ever wanted to sell.

 

Same as the shitty original motors from the 70s, I'd rather have a color I like than, let's say, a brown one with original paint.

 

I have a 78 that will be painted Crystal Red Metallic like my C6. I gave up trying to keep things original a long time ago. If I had a museum I would have a museum piece. But I have a car that I want to enjoy when I take it out. The red is going to put a smile on my face where the silver anniversary two tone looks like every other 78. I think the color question is like a lot of other decisions we have to make. What do we want the car to be. Fun. Fast. Or a trophy reflecting Corvette history. Or an investment. I opted for fun. I would also like to volunteer my 78 to any of your paint seminars.

 

When I got my car, it got hit and run by my friend's neighbor. My co-workers took it home, repaired the damage, stripped over a dozen different color paint jobs and repainted it red. I think the trim tag said it was originally white. The day after it was painted, threw a rod. The engine that was in it had come from either a taxi or police car. Have since put coil-overs up front, will do the rear soon. There won't be much original '74 stuff on this car when I'm done, which is fine by me because '74 and up were pretty shitty performance-wise when stock.

 

thanks guys, I've been weighing this decision for a while, I don't have an ugly color (white) but im in Az and every car is white, i known its been done to death but I have always loved a red corvette and with the black interior would be a great combination, the car is currently factory straight but want it Lazer straight with the stock 1980 red polished to glass.
I no loner teach oem refinish classes but still have access to the training center and booth.
Here is your "crystal" 3 stage red i put on my FF 33 hotrod... but it had an LS Holden with 6L80

 

Ive built many cars but never built my own motor, thats been the one area i would pay someone to do or trade out work, ive been considering cutting my teeth on this car and just getting a small block and building it, after reading on this post I think I'm going to do just that, it will be fun to learn along the way even if it doesn't get installed till years down the road.

 

I'd buy the car you could afford with a better motor than worrying about numbers.....don't live life like this ...

 

Absolutely! But white is at least the second best color for C3s, so I'm not sure what @Golfobsessed hopes to improve on. I'm fortunate that both of my cars sorta match their trim tags, though both have been repainted, including one in an amazing microflake metallic black.

To the OPs point, with all other things being equal, finding a car in the color I wanted would also be worth more to me than a matching trim tag, since a color change is (for someone who can't do it themselves) a much bigger deal than an engine swap.

 

what i "hope" to improve on is the color i prefer... not everyone likes the same color which is why I originally didn't post what color I wanted to change to... to avoid people thinking their color was the only option
this was a value deduction question and not a color preference question

 

And if you find a buyer someday who also prefers red, it may be worth more to them than an otherwise identical white C3 with a matching trim tag. Or not. There are lots of red C3s out there, too.

But if that's what you want, and you have the ability to do it and make it better than it is now, why does it matter what a hypothetical sale price might be someday? Make the car what you want it to be, and enjoy it!

 

And for me a '70 LT1 missing it's original motor would be a bigger deal than say a '76 L48.
Hagerty says subtract 10% from the value for a C3 with an automatic...

 

Matching numbers doesn't seem to matter much on C3s, at least from 1974-82. Very few of these cars are really considered something special worth preserving in original condition. They are all better with more power.
If you had a '67 L-88 my opinion would be different.

 

I agree and thanks, of course I want it what i want, i dont have intentions of selling but never know the future, I can't imagine hurting value too much but wanted to run it by the group to help maybe justify my decision or push me off the fence either way, thanks again

 

While this is an interesting topic, hijacking this members thread about NOM engines might not be the best way to ask it.

Try starting your own thread to explore this fully, please?