Did I just get hosed?

[gilberttitan08]

I just bought a 340 crankshaft, the last four casting numbers are only visible which are 3457, I know 68 cranks are 2532457. Are these numbers correct for a 340 forged crank?

 

[Beekeeper]

You can look and tell the difference between forged and cast. Take a look at the parting lines on the throws a forged will have wide parting line (1/2" is so) and the cast will be thin.
The parting line is the raised area that runs parallel with the center line of the crank
Opposite side of the counter weights.

 

[gilberttitan08]

It's a thick parting line, 1/2"-3/4" thick.

 

[Beekeeper]

Sounds like you didn't get hosed:hello2:

 

[gilberttitan08]

What are other signs of a "340 crank" being true?

 

[Beekeeper]

318 and 340 have the same main journal size at 2.500 the 360 is 2.800
easy to tell 340 from 360 and they never made a forged 318 crank as far as I know

 

[HawkRod]

Remember also that in 1973 (maybe 72?) the 340 crank changed to be cast and shot peened. That I what I have in my 73 340. Bottom line is there are 340 cranks that are both forged and cast. They balance differently too.

 

[Cranky]

Looks to me like you have a steel crank.

318 and 340 have the same main journal size at 2.500 the 360 is 2.800
easy to tell 340 from 360 and they never made a forged 318 crank as far as I know

Yes, forged steel cranks were made for 318's....

 

[Beekeeper]

thanks for the info on the 318 cranks. thats why i like this site I always learn something new

 

[patrick66]

It was 1973 when the 340 received the cast crank - and the one-year-only balancer.