How can you tell the difference between a 330 and 350

[320400425]

How can I tell the difference between a 66 350 and a 66 330?

 

[TURNA]

Numbers on the front of the block above and behind the water pump

 

[320400425]

I have looked at those numbers but the casting resources online say it could be a 330 or 350.

 

[320400425]

What about the heads I had built for the 330 fitting on the 400

 

[TURNA]

heads could be off anything they just bolt on

What is the number on the block?

 

[320400425]

381917 on block and number 2 on heads

 

[TURNA]

That should be a 330 do u have the pan off it?

Does it have the steel crank?

 

[Olds 307 and 403]

The 350 came out in 68, so no 66 350. The 68-76 350 casting number is 395558. The only real difference like all SBO is a different bore for each engine size. As in when they enlarged a motor, they increased only the bore size.