New to the Corvette thing, What are the clues to determine if your car is a small block or big block?

Also My 71 has the factory rivots holding on the data plate and the vin plate. The car is Ontario orange under the plates but the paint code calls for yellow and there is no provision for the wiper cover door assy. No holes were ever drilled for the vacume motor etc, but the orange paint is all around those areas and the vin is held on with the correct stared rivots. Any help or input would be appreciated.

Thanks

 

hmmm sounds like one of them multivettes. you know the kind where the mix and match parts from multiple years to get the look they want

 

BB has wide, flat valve covers, SB has more rectangular looking covers.

BB exhaust manifolds have individual runners and exit rearward, SB have a "ram-horn" type that goes down in the center.

 

The easiest way to tell a small block form a big block chevy is to look at tthe exhaust ports - if they are evenly spaced, it is a BBC, if the 2 middle ones are side by side, it is a SBC.

 

just floor it that should tell you

 

Hello,

Is your question how can you tell if the engine is a small block or a big block, or is it how can you tell if your car was originally a small block or big block car from the factory.

If it is a big block, usually the size of the valve covers is a key item that will tell you. The valve covers are almost 2x the size of a small block cover.

If you want to know if the car was ordered as a big block, you need to look at the vin number. For 1971 cars they did not list the specific engine type. That may have started in 1972.


1971 Corvette Identification


VIN Tag Information
194371S100001 - 194371S121801 (coupe)
194671S100001 - 194671S121801 (convertible)
Digit Definition
1st Division: 1 = Chevrolet
2nd / 3rd Series: 94 = Corvette
4th/5th Body Style: 37 = 2-door coupe, 67 = 2-door convertible
6th Model Year: 1 = 1971
7th Assembly Plant: S = St. Louis, MO.
Last 6 digits Production Number starting with 100001 - 121801

Engine Suffix ID Numbers
CGT: 350ci, 270hp (automatic transmission)
CGY: 350ci, 330hp (manual transmission, ZR1)
CGZ: 350ci, 330hp (manual transmission, LT1)
CJK: 350ci, 270hp (automatic transmission)
CJL: 350ci, 270hp (manual transmission)
CPH: 454ci, 365hp (manual transmission)
CPJ: 454ci, 365hp (automatic transmission)
CPW: 454ci, 425hp (aluminum heads, manual transmission)
CPX: 454ci, 425hp (aluminum heads, automatic transmission)

 

Bigblock is, well, you know, BIGGER!

 

You can fry a pancake on the big block's vlv covers!

Bad*ss in short...

carbster09

 

Check http://www.71corvette.com/spec.html
and you can find that

ENGINE CASTING NUMBER:
The engine casting number is located to the left of the distributor on the top rear of the block.
"3970010" = 350 CID
"3963512" = 454 CID

 

You can tell by how many stops you have to make at the gas station.