SBM Crank Identification Help!

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Hyper_pak

Hyper_pak

Old School Chrysler Fan
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I have 4 SBM cranks here and I do not have any way of knowing what they were used in.
Is there a chart somewhere showing casting numbers or a way to ID them?

1 is marked 2658278. 1.8 crank register. 2.49 main
1 has a partial number, 46577 on the number 2 main counterweight. 1.5 crank register. 2.50 main.
Last one has no number. It has a double roller crank sprocket. 1.8 crank register. 2.49 main.

I was able to ID this one:
1 is marked 3418640. 1.8 crank register. 2.78 main. This is a 360 cast crank.

Any help?
 
Can you post a couple pictures of each?

I have found some some crank ID’s in the past by doing an online search. Have you tried that and no hits?
 
Rocket said:
Can you post a couple pictures of each?

I have found some some crank ID’s in the past by doing an online search. Have you tried that and no hits?
Click to expand...
Hyper_pak said:
I have 4 SBM cranks here and I do not have any way of knowing what they were used in.
Is there a chart somewhere showing casting numbers or a way to ID them?

1 is marked 2658278. 1.8 crank register. 2.49 main
1 has a partial number, 46577 on the number 2 main counterweight. 1.5 crank register. 2.50 main.
Last one has no number. It has a double roller crank sprocket. 1.8 crank register. 2.49 main.

I was able to ID this one:
1 is marked 3418640. 1.8 crank register. 2.78 main. This is a 360 cast crank.

Any help?
Click to expand...

Your first crank, the mains have been cut .010 as they measure by your account 2.49, standard is 2.50, with no pictures I can not tell you if it is cast or forged; you can figure that out just by looking at it; (reference your 360 crank parting line is narrow, cast) wide parting line (forged), narrow parting line (cast). Possibly came out of a late 273, maybe 318, 340.

Your second crank, with the small register could be 273, or 318 Poly, most likely has wide parting line (forged), mains measure, buy your account, standard

Your third crank, mains have been cut .010, the double roller crank sprocket is of no real importance, chain and gear set could have been changed out long ago. Check for wide, or narrow parting line, just another ordinary small block crank.

The crank you have identified as a 360 crank has had the mains cut .030, as you have measure them at 2.78, standard is 2.81, we know it is cast, look for the letters CFD cast into it, allegedly these were better cranks, who knows

Does this help?
 
Forged are easy from 20 feet away: if it has rounded throws, its forged. sharp 90's on the counterweights as if molded (cast!) are a dead giveaway. Specific models from a crank is gonna be tough unless its a forged with holes in the throws, then its a 340. Both these are forged...guess which one is a 340 spec?
100_1405-jpg-jpg.jpg


Ooh, one has a huge scallop out the flange too....? A great place to break if FedEx drops it in transport! :(
 
1st 273 crank.
2nd, 457# would be the steel 340 iirr
How many holes on the flange?
Basically all the small registers are 273 or pre 68 cranks
 
A crank with the small converter register would be a 273 forged crank. Poly cranks have the big register.
 
Thanks for all the help.
I guess there is no listing that would reference a number to application.
My Galen white books don't have crank numbers.
I have figured out that the cranks with no holes through the rod journals are 273 or 318, one pre 68 and one post.
The one I am going to use is the one pishta said was a 340 crank.
It has the large register and the double roller gear.
No number stamped anywhere.
I know the gear doesn't mean anything, but I have had these for years.
Not sure where I got it from.
It needs some work, but should be ok for what I want to do.
340 Crank.JPG
 
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