Hi Guys,
Is there a definitive way to tell an original '68 small block car from an original big block car? (Fuel line routing, axle shaft size, etc.?
Looking at a '68 which is missing motor and exhaust. Owner thinks it was a big block car.
Best,
Greg

 

Here are some clues, but by no way "definitive" because all of these are easily changed.
1) single fuel line for Holley equiped Vettes----400/435/430hp
2) Tach red line---5600 for 390 and 400hp----6500 for 435/430hp
3) radiator, radiator support and extension, radiator shroud, no overflow tank
4) front sway bar is larger
5) must have rear sway bar
6) half shaft "caps" vrs. u bolts
7) code on rear end case
8) 7 leaf rear spring vrs. 9 leaf
9) front coil springs are shorter/stiffer, and rear shock mounts have a different angle--very difficult to determine when installed, and again, easily replaced.

I'm sure others will add more,
George

 

well i dont own a 68 but do know how to anwser your question. sorry not a owner.

 

George about wrapped it up,and I'm not trying to be negative,but all those things are easily changed.What the owner has is a car that may have been a BB,but will NEVER be the same BB again.Unless it has all the paperwork,and was some rare BB......don't get sucked up paying for a car that was once was........

 

Not a '68 owner, ('69), but I don't offend too easily.

Often overlooked clue is the emissions/tune-up sticker on the firewall. A two-letter code is specific to engine/trans. If it is there and appears original, this is excellent documentation.

Likewise, if it is missing or painted over, you're out of luck.

Steve

 

the tank sticker will tell you for sure if its still there and he is willing to let you pull the tank??

 

or tell him to pull it and prove it to you for the money he`s askin!

 

Thanks George,
This is just the information I was looking for.

I will see if the emission sticker is still on the car, Steve.

Best,
Greg

 

The 7 leaf is part of the F41 suspension, not all BB's had it

 

I respectfully disagree. 7 leaf is standard big block. My 68 427 does not have F41 but has the 7 leaf.

 

Bottom line is it doent have the motor in it now so I wouldnt pay any extra money for it even if it was a BB because it isnt one NOW!!

 

A big block hood (if real) is worth a fair bit more than one for Sb...so if it has one you could add to the price some.
All of the big block parts that are present have a value....
Many would pay an extra grand for an ex big block car.....because it takes less work to put one back in.
Now if these items are not usable than they are not worth any more than a small block car.

 

Thanks for all the input guys.

Here's what I've found:

The car has a fuel feed line and a return line.
5600 red line tach.
There is a rear sway bar.
Half shaft caps.
Seven leaf rear spring.
It does have what appears to be an original big block hood.

I do not know what the visual difference should be regarding the radiator, support & extension. There is an overflow tank but it's clearly an add-on aftermarket piece.
I don't have the rear end code yet. (or the code off the 4 speed trans for that matter).
The emission sticker is still in place but painted over. Some gentle scraping has not revealed much readable data.

Your thoughts?

Best,
Greg

 

The bottom line - pay for the quality of the car, not what it was or should be but what it is.

I don't think paying out the nose for an original is wise if it isn't worth it quality wise, with a few exceptions. Those being really rare cars like L88s, original ZR cars, and such. The "1 of 4 oyster colored interior L82 4 speeds" is a joke and worth maybe a $5 premium. After all, all I have had have been 1 of 1 due to the VIN.

Many get hung up on values "because Barrett Jackson says it is worth ..." or because they see that a "196x Corvette with ...." sold for some outrageous amount.

I think a big block car is worth more than a small block, IF YOU WANT A BIG BLOCK. And if you have a big block car that is in all stock original form, but not necessarily original engine, pay for the quality.

For example, many pay more for an original engine than an NOM, but yet the NOM maybe be in completely stock configuration, enough to win an NCRS Flight if they chose to do that, while the original motor car may have a lot of non-stock things like headers, Pep Boys water pump, spark plug wires, and so on.

All of that being said, determining a car anymore is as much about reading the car and owner as just checking the items off a list. Too many cars have been made, and in the 40 years since that 68 was made, it could have had too many to count changes. In the '70s, these were worth $2000 to $2500 for awhile, with the 68 and '69 being the lowest valued ones in the mid 70s. As such, they became the cheap hot rod fodder for anyone wanting to build fast or custom Corvettes or especially those wanting road racers since the mid year had much more air drag at speed.

So you need to read the age of parts to decide if those are factory or put on by someone later on. And remember, it is hard to tell if a part was installed 30 years ago or 40 years ago, even though most can tell if it was 40 or 5 years ago. And surprisingly, many can't tell the difference of 5 years ago or 40.

So if you have doubts, take an expert with you. The $100 to $200 you might pay them can well be worth it.

 

Mark,
Thanks for the input but most of your points are academic at this point. I am not concerned with perceived values, original numbers, what it might be, etc., etc.
And, while I appreciate those who are looking out for my safety and helping to keep the breed clear of counterfeit cars, I am simply looking for some valid info to I.D. a '68 as a small block car or big block car, not opinions of what I should be paying for.

George's reply seems to be the most valid and has led me to believe this was once a 390 hp car.

I have very few doubts and, if you've read my profile, I guess I could consider myself a bit of an expert. I still don't know it all though, that's why I don't mind reaching out to someone here that might have a little more detailed info on a particular year/model.

Thanks again, I do appreciate the input.
Best, Greg

 

same here

Hi Greg

Do you really care what it was .........it doesnt change anything or make it worth any more. It can only be worth less as it's no longer original it's not what it once was & will never ever be again.........
dont harp on it & IMO I wouldnt pay any more for it being " FORMERLY " a big block .......

 

Yes.
Yes, I really care what it was, because if it was originally a 435hp car I would locate a period correct intake, heads, carbs & block, deck it, broach it and restamp it so no one could tell it was counterfeit, then sell it at Barrett Jackson for a small fortune.

.......satisfied?

 

Well heck, now that you told us what you really want, we can help you get there.

Unfortunately, '68 was less different between SBC and BBC than previous years and most of the items that would be a tell-tale are items that may have been switched out in its life anyway. Rear ends many use as an indicator, but they read those backward. The presences of caps on the axle stubs means the rear end came from a big block car, not that the car is a big block. And since so many in the performance years of the '60s and '70s would swap in a 4.11 or even a 3.70, the odds that the rear has been changed is very high that it came from a big block car as that is where most of those came from.

Radiators were different, and most didn't change those. I believe in '68 the core support was still different for aluminum SBC vs copper/brass BBC but I can't tell you how exactly. Larger opening, I think. Anyway, these are less likely to be changed except in a complete front end change due to a wreck or a fake clone, which is an '80s and newer phenomenon.

Gas line is single on the 435 hp but I cant' think of a difference on the 390 and the SBC. In midyears, there was a difference in length so that the gas line ended at a different spot on the frame and had a slightly different angle in midyears, but I don't think that occurred in the 68.

Usually I have found that rather than look for indicators to proof the car was something, it is easier and quicker to look for those that prove it wasn't. And then weight the disprovers on how likely they were to have been replaced in the normal life of a Corvette (wear, age, failure, and wrecks).

The 7 leaf spring is an example. In the '60s and '70s, drag racing and street racing from light to light was king for many, so the 7 leaf was quickly installed to get the better launch, so much and so early in the car's life, most think they were original in all big blocks. But the 9 leaf was standard even with the big block. And the ease and "common-ness" of replacing a spring weights it to nearly worthless as an indicator unless you can somehow verify it has never been removed.

Check the starter number if the car is old, in a garage for the last 15 years, or something. Most changing engines used as many accessories as possible off the old engine, and the starter wasn't one interchangeable in '68 with a 14 inch flywheel on the BBC and a 12 inch on the SBC. So starter numbers are often wrong from being a parts store replacement when the BBC was installed. However, weight it accordingly as the starter was not that uncommon to simply need replacing.

 

Now THAT'S an insightful post.
Thanks, Mark

 

I`m curious. Whats the starter have to do with it, the engine is missing and would logically not have a starter either. They are merely a cast iron nose starter specific to a early BB available everywhere. BB Chevys, Chevelles, Camaros, and Vettes all shared the same starter nose.

This thread has some independant significant value to me as I too dont know the differences, nor wasn`t ever interested until recently because of the disparity in values never having owned a SB C3.