sobmstr

Have an opportunity to purchase a '69 convertible, owner says it's original 390hp 4-speed car, although engine is not original.
Owner has no documentation.
Are there any tail-tale signs I can look for to confirm original big block car?
Have not inspected since in different part of the country, but will plan trip if it appears worth the time/$.
Any advice would be helpful.

Thanks

ddawson

A few things, Tach, Rear sway bar, Caps instead of straps on the 1/2 shafts.

My L36 redline is 5,600

BBCorv70

That year does not provide proof of original engine type in the serial number, you'll need to do some detective work. The tach is the most difficult item to replace or upgrade, maybe start there. Not likely to be swapped out without a restamped block, not worth the trouble. Find out what the tach red line is, they were different for big blocks. I believe that year had more than one. Next is the hardware fastening the rear half shafts to the differential, they should be caps, not straps (u-bolts). Does it have a rear sway bar? Radiator support should be 27-1/2 wide. There are a few other clues which can be spotted by inspection. The ultimate proof would be the tank sheet if it exists.

Why is it important to you the car was originally a big block? It won't make any difference to the numbers crowd, it's now a NOM. If the car was an original big block, all parts unique to the BB still there, the car can still get top flight in NCRS judging providing the block is 'correct', proper casting number, date codes within reason. Just tossing it out there.

Would you be comfortable with a NOM? If you're looking for a driver, a NOM may work well, cheaper price for essentially the same car. Judging is still possible (NCRS) though some will never accept the car as real.

Be aware NOMs most often sell for less than numbers cars. Another way of stating this is people pay extra for 'numbers'. Be sure to do some research on current going prices for either type, do your homework.

LS4 PILOT

I always thought BB cars that a SB replacement often sat a little funny in front . The front end looks like 4X4

If somebody stuck a BB back in ..to replace the original....that would be ok ....no body but you will have to know . It will same fun., without worrying about damaging a born with motor.

Convertible C3 are Phunn

Alan 71

Hi s,
I don't think there's any reason to pay any more for this car than you would for a sb car without documentation.
At this point I think the LACK of documentation is the issue so it doesn't matter what the engine MIGHT have once been.
I'd think you'd judge the car by what's in front of you when you see it.
Certainly the first thing to settle would be the rust issue….. and then the completeness and over all condition of the car.
Good Luck!
Regards,
Alan

CA-Legal-Vette

I mostly agree with what Alan said above but if your goal is to have a BB car but aren't willing to pay the premium, I think this one might be worth a little more. If all of the original BB parts are still there, especially the tach and rad support, it would be worth a few hundred more than another NOM convertible to me. Again, the real key is condition, especially of the frame and birdcage.

As long as you like the car and pay NOM pricing, these can provide you with a lot of freedom of choices. You can "reserect" the car that it was or go the opposite way and maybe add an LS.

joewill

the more big block parts the car has on it, the more some folks will pay..

some say if not original motor, then price automatically falls to the low ball not original anything price no matter what the condition, other original parts, or proof of former big block (via doc).

even with correctly dated and original heads, carbs, intake, exhaust, tranny, rear end etc. A car with a non original cylinder case, some say its a bastard.

I disagree. Yes, the cylinder case is the most cost incremental when it comes to originality, but condition and other original parts will be a positive increment to the low ball price.

Hard to tell what that price should be. you will lose the purist buyers if the car is without the original block. but you will gain potential buyers the more BB parts it has.

Nothing wrong with a NOM car, as long as you pay correctly for it. Know your requirements, and if you require a original motor, understand what the pros and cons are if you decide to play that game.

vettebuyer6369

While it's interesting that it started out as a big block, the fact that it used to be a big block has no extra value to me. I'm not sure what the upside is in determining that it was an original biog block once in its history, other than a good story. Unless of course, the plan is to install a restamped motor.

The car could be a great car and certainly has value, but I don't understand paying a dollar more for an NOM that used to be a big block as opposed to an NOM that wasn't.

BBCorv70

I agree for the most part. IMHO we're talking about two entirely different classes of buyers, buying these cars for different reasons. To someone with a collector mindset, once the original block is gone, it's a severely damaged antique, value drops quite a lot. Only reason collectors will pay more for a big block is relative rarity and desirability. Documentation, proof of originality is very important given the number of restamps running around out there.

The other class of buyer is buying the car to be a driver, originality isn't so important, probably looking more for performance. I disagree with Alan71 on pricing here. The buyer looking for a driver, big block, will often pay more due to lack of supply compared to small blocks which are much more common. I've seen this for as long as I've been involved with cars, big block cars always fetched a higher price even before originality was a consideration. I've owned several small blocks before moving to big blocks mainly because I couldn't afford to pay the extra cost for the big block. To say a big block is worth no more than a small block pretty much assumes from a buyer's perspective, people buying drivers, they're pretty much the same car, equally available, equally desirable. I'll add a high performance small block will also fetch a premium over a base model.

About the only attribute both collectors and others have in common is condition.

So far as prices go, no denying some people will pay quite a lot more for a numbers car over a NOM. From what I see, studying price history for the last 10 years, Hagerty's data, most Corvettes dropped value a bit after 2008 and have remained rather flat since then. The big $$ cars may have lost more value than the cost of a base NOM. It appears to me buying a numbers car will tie up more $$ during the period of ownership. I haven't seen evidence from an impartial source they increase in value significantly over a NOM. If the numbers car was bought at a fair price after around 2010, the owner will probably get their money back. Volumes of sale price data for NOMs is a bit harder to come by since most pricing guides don't break out pricing based on NOM or original, few sellers clearly state the car is a NOM. Obviously NOMs have risen in value, otherwise they'd be nearly free today. If a buyer desires numbers and is willing to pay the extra, nothing wrong with that. Id' say numbers are very important if I were buying a survivor or a low ownership, low mileage original. From what I've seen, numbers buy and sell at higher levels.

Interestingly, Hagerty has a feature which allows the viewer to overlay appreciation curves for multiple vehicles for comparison. It also allows overlay of stock market performance over that same period. Corvettes make pretty poor investments in this context if the primary reason for owning one is investment. Strangely, my old 69 Mustang Mach 1 shows much stronger appreciation than my 70 Corvette big block. When faced with a choice of selling one, I chose to keep the Corvette. I still prefer the Corvette, never thought of it as an investment.

BBCorv70

More or less agree. If the car currently has a big block I would pay more than I would for a small block. So far as whether it was originally build with a big block... If it were originally a factory big block, still had all the correct parts, I'd pay more than I would for one without. A car which was originally a small block, had all upgrades done to match the factory build, a tribute, is pretty much the same IMHO. I lean to preferring at least built as the factory did in the day.

20mercury

kenvette69

Agree with postings. Tach is the easy identifier, you can pull the tach is you are super interested. there is a date code on the housing, compare that to the build date on the trim tab. If it's close, most people won't go to that length. They can change out an engine, but tear the dash apart to change a date code on a tach, not likely.

Check the rear end code as well. Is it a heavy duty code? Likely a 427. Half shafts, rear sway bar, front sway bar larger and look at single fuel line for L88, L71 435 car. won't help you on other L36 390, L68 400. Both have two fuel lines.

Run the Vin, just to see what comes up. You may find it was for sale with some other information in the past. Finding previous owners is near impossible, can run into "dead" ends there too.

So there are clues to follow, you can dig pretty deep. Good hunting.

Danish Shark

The L36 isn't exactly a rare car, about 25% of the 1969 cars were L36, so without the original engine you shouldn't pay more for that.

If it has a NOM big block it will still cost more than a NOM or standard matching smallblock.

Total: 38,782
L36 427ci, 390hp Engine 10,531
L46 350ci, 350hp Engine 12,846
L68 427ci, 400hp Engine 2,072
L71 427ci, 435hp Engine 2,722
L88 427ci, 430hp Engine 116
L89 L71 Aluminum Heads 390

BBCorv70

Not so sure I agree. The added value over a small block NOM would be in the parts unique to the big block, assuming the buyer is looking to install a replacement engine, keep the factory configuration. In this case the added value would be the cost of all unique parts if they had to be tracked down. It may not add any value if the buyer is planning on installing a SB or an LS engine, factory big block parts wouldn't matter?

Just the fact it was originally configured as a big block doesn't add any collector value (unless we're talking about an L88), it will always be a NOM.

Either way, condition is a major consideration, rust, paint, etc...

427vette66

Thanks your help everyone. I think i'll make an offer once I take a look at the under carriage, I really like the idea of saving for PA weather.

449er

Get the 22k & run don't walk to pay this guy

pltmgr

Since the OP was 8/2016, this cat has been or sale 2.5 years?

MelWff

something isnt right if the car has been for sale for such a long time

jackson

I know this is old from 2016 … with that context in mind … I ask WTH is going on w/post 15? ...p15 marks resurrection … then look at p15 content ...WTH?

RMVette