I am looking at Buying a 68 Vett. The car has had the mechanicals rebuilt, and a 350 V8 engine installed. The owner says that the car was orignaly a big block car. How can I make sure of this claim, and what size it was (396, or 427)?
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Only way to know.....
is to look at the paperwork, if the owner has it, or if the seller is the original owner of the car, look at the Protecto plate, it will have the engine stamp on it. If the seller is not the original owner, and previous owners transferred the warranty to their names, the engine id will not be on the protecto plate.
Others sources, but this is a looong shot, is build sheet attached to the gas tank. If it is there, it is probably deteriorated an not legible. Also some people said a build sheet is tucked behind the radio, but I've never seen one there.
Only the '65 Corvette had the 396, 66-69 came with the 427's. -
Only way to know.....
is to look at the paperwork, if the owner has it, or if the seller is the original owner of the car, look at the Protecto plate, it will have the engine stamp on it. If the seller is not the original owner, and previous owners transferred the warranty to their names, the engine id will not be on the protecto plate.
Others sources, but this is a looong shot, is build sheet attached to the gas tank. If it is there, it is probably deteriorated an not legible. Also some people said a build sheet is tucked behind the radio, but I've never seen one there.
Only the '65 Corvette had the 396, 66-69 came with the 427's.Comment
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Re: Only way to know.....
Dale, there are clues you can get from a close inspection of the car's undercarrage, Get a copy of the '68-68 NCRS judging guide for some additional information, but the first thing I would look at is the rear of the car for a rear sway bar assembly. These were exclusively used on BB cars. While you're ubder there, look at the axle u-joint attachment to the differential. BB uses a cap screw assembly, SB uses u-bolts. Next, look at the hood. BB used a different hood and holes will appear in the hood along the raised center portion of the hood for "427" emblems. Check the tach redline against the judging guide. Different redline tachs were used with different engine combinations. If these things check out, then you might want to do a search for past owners and documenttion.Comment
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Re: Only way to know.....
Dale, there are clues you can get from a close inspection of the car's undercarrage, Get a copy of the '68-68 NCRS judging guide for some additional information, but the first thing I would look at is the rear of the car for a rear sway bar assembly. These were exclusively used on BB cars. While you're ubder there, look at the axle u-joint attachment to the differential. BB uses a cap screw assembly, SB uses u-bolts. Next, look at the hood. BB used a different hood and holes will appear in the hood along the raised center portion of the hood for "427" emblems. Check the tach redline against the judging guide. Different redline tachs were used with different engine combinations. If these things check out, then you might want to do a search for past owners and documenttion.Comment
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Good Point on the tach....
forgot obout that: 390/400 HP redline at 5600, 435/430 HP redline at 6500.
The rear sway bar is not a good indicator of a BB, as SB guys used to add the BB front & rear bars for better handling.
In our club (NCCC affiliation) all the SB guys upgraded to the BB sway bars.Comment
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Good Point on the tach....
forgot obout that: 390/400 HP redline at 5600, 435/430 HP redline at 6500.
The rear sway bar is not a good indicator of a BB, as SB guys used to add the BB front & rear bars for better handling.
In our club (NCCC affiliation) all the SB guys upgraded to the BB sway bars.Comment
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Re: Good Point on the tach....
Yes I'm very familiar with NCCC, used to be Governor of an NCCC club. In my opinion, NCCC modified cars are a very small percentage of the cars available as candidates for "restoration"Comment
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Re: Good Point on the tach....
Yes I'm very familiar with NCCC, used to be Governor of an NCCC club. In my opinion, NCCC modified cars are a very small percentage of the cars available as candidates for "restoration"Comment
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Re: Big Block Identifiers
George, a couple of months back there was discussion of the rear sway bars on big block frames, and that the attaching nuts were welded on the inside of the frame during its fabrication -- so looking a little closer, you could tell if they were added post-factory. Why GM didn't just build 'em all with nuts so the big and small block frames would be identical is one of the accountants' little secrets.
How about the gas line (rear to front) ? On mid year cars it's a little longer and has slightly different angles near the fuel pump, as the pump mounting boss on a big block lies forward of the same point on a mouse motor.Comment
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Re: Big Block Identifiers
George, a couple of months back there was discussion of the rear sway bars on big block frames, and that the attaching nuts were welded on the inside of the frame during its fabrication -- so looking a little closer, you could tell if they were added post-factory. Why GM didn't just build 'em all with nuts so the big and small block frames would be identical is one of the accountants' little secrets.
How about the gas line (rear to front) ? On mid year cars it's a little longer and has slightly different angles near the fuel pump, as the pump mounting boss on a big block lies forward of the same point on a mouse motor.Comment
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Re: Good Point on the tach....
I found the Corvette Order Copy between the dash and the steering col while repairing my dash components almost two years ago. It is identical to the one which is supposed to be in the tank. Others have found it under the radio or so. That could be a good solution if you are lucky. The sway bar was discussed some time ago here but no real conclusion was stated as some owners with SB certified the nuts where welded in spite of the bar abscense (me included). All best from Argentina Roberto NCRS #30019 RMCComment
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Re: Good Point on the tach....
I found the Corvette Order Copy between the dash and the steering col while repairing my dash components almost two years ago. It is identical to the one which is supposed to be in the tank. Others have found it under the radio or so. That could be a good solution if you are lucky. The sway bar was discussed some time ago here but no real conclusion was stated as some owners with SB certified the nuts where welded in spite of the bar abscense (me included). All best from Argentina Roberto NCRS #30019 RMCComment
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Re: 68 motor size
Dale----
Bill Clupper's suggestions are good ones and they are exactly what I would look for to distinguish an original big block from small block. One thing I'll add, though, is this: if the car is a 4-speed car, all 1968 manual trans small blocks used an external radiator supply tank mounted on the right side inner fender. If the bracket for the tank is still there, or if there are obvious signs of its former presence, the car was originally a small block car, for sure(unless it was one of the 80 L-88s made that year, since the L-88s also used the external supply tank). All other big block 1968s used a radiator without an external supply tank, both automatics and manual trans.
The one thing that is important, though, is to look for ALL of the differences mentioned in Bill's and others' posts. That's because anything could have been changed. You get the best information if you look at everything and use the information as a "composite".In Appreciation of John HinckleyComment
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Re: 68 motor size
Dale----
Bill Clupper's suggestions are good ones and they are exactly what I would look for to distinguish an original big block from small block. One thing I'll add, though, is this: if the car is a 4-speed car, all 1968 manual trans small blocks used an external radiator supply tank mounted on the right side inner fender. If the bracket for the tank is still there, or if there are obvious signs of its former presence, the car was originally a small block car, for sure(unless it was one of the 80 L-88s made that year, since the L-88s also used the external supply tank). All other big block 1968s used a radiator without an external supply tank, both automatics and manual trans.
The one thing that is important, though, is to look for ALL of the differences mentioned in Bill's and others' posts. That's because anything could have been changed. You get the best information if you look at everything and use the information as a "composite".In Appreciation of John HinckleyComment
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