Identifying '66 Big Block...?

[Raymond W.]

A member in my local Corvette Club has a friend who is trying to identify if his '66 car was an original big block car. When he purchased it some years back, he was told that the big block engine had been stolen and it was replaced with a small block. I told him that without any as built documentation, it wasn't. Are there any particular components on the chassis, brakes, suspension, or anything else that would be synonomis with a big block vehicle?

[Mike M.]

Re: Identifying '66 Big Block...?

Sort of, Ray.
There are indicators, but, they are not conclusive as they could have been added for effect.
There are several very descriptive threads available through the archives.
HaND

[William C.]

Re: Identifying '66 Big Block...?

Radiator, rear sway bar, TI if 425hp (check tach redline) Rear axle attachment to differential, just the easiest ones.

[David S.]

Re: Identifying '66 Big Block...?

Hi Ray,

I hope you doing well. There are several factors you and your friend should consider while looking over his car. I have listed them below.

1 - The accelerator lever on a BB is different than that on a small block
2 - A big block will have a 7/8 (standard suspension) or 15/16 (F41) front sway bar whereas a small block will have a 3/4 front sway bar.
3 - The front springs on a small block are different than a small block.
4 - Big Block cars have a rear stabilizer bar, whereas small blocks do not.
5 - Big Block car have rear different caps holding the half shafts to the rear whereas small blocks use U nuts similar to how the driveshaft connects to the rear and transmission.
6 - Is there any evidence of a TI? Or a ballast resistor?
7 - What does the tach / oil pressure gauge.
8 - A big block will have a 90 degree bend at the end of the fuel line closest to the fuel pump. Small blocks have a 45 degree bend.

Hope this helps,
Dave

[Tom D.]

Re: Identifying '66 Big Block...?

If the body has never been off the frame, the fuel line would likely still be there...

td

[Raymond W.]

Re: Identifying '66 Big Block...?

Radiator, rear sway bar, TI if 425hp (check tach redline) Rear axle attachment to differential, just the easiest ones.

Bill, what would the difference be on the tach redline? Ray

[William C.]

Re: Identifying '66 Big Block...?

Tach redline starts at 6500 for the 427/425 and 5500 for the 427/390 (same as 300 hp oil pressure is 80 lb for 425 hp. Oil gauge is 60 lb for 390 hp but according to the newest Judging guide there is a difference in the gauge face printing. Best to buy the manual if interested in that level of detail.

[Ronald L.]

Re: Identifying '66 Big Block...?

If the car lived at any time in the rust belt AND the rear sway added later there should be pitting underneath those attachment points AND if it was original, those two surfaces should look like they have never been been apart for 44 years.