can you look at a picture of my Crank?

[70blackfish]

can you tell from this picture if its a forged or cast crank?

[JOJABOY]

And you know I looked.

[Mister-B]

Originally Posted by JOJABOY

And you know I looked.

Lol. Between this thread, and the "how long is your dipstick" thread, who knows what's going on around here
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[JOJABOY]

Some folks are just WRONG! ha-ha- What's killing me is the fact that I just had surgery and am pretty much bound to my couch with nothing to do but surf craigslist and read peoples sillyness on here. I did get to peek under hood of a friends truck today. Didn't check out his crank but I did pull his dipstick.

[71K20chevy]

To me that looks more like a forged one, but I'm no expert

[Livrat]

Its hard to tell from the angle of your picture,
If the portion I have highlighted shows a "seam" thats approx 1/4" wide its a forged steel crank, if the "Seam" is very thin its a cast crank.

[Mister-B]

Originally Posted by JOJABOY

Some folks are just WRONG! ha-ha- What's killing me is the fact that I just had surgery and am pretty much bound to my couch with nothing to do but surf craigslist and read peoples sillyness on here. I did get to peek under hood of a friends truck today. Didn't check out his crank but I did pull his dipstick.

Lol. I think the meds might be making you slap happy
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[glider_6969]

Originally Posted by Livrat

Its hard to tell from the angle of your picture,
If the portion I have highlighted shows a "seam" thats approx 1/4" wide its a forged steel crank, if the "Seam" is very thin its a cast crank.

Since you have the motor this far apart are you able to see any name stamps or numbers anywhere?
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[ItsRandy]

Originally Posted by 70blackfish

can you tell from this picture if its a forged or cast crank?

I think the question you want to ask would be if your crank is nodular iron or steel. I don't think GM cut any crank shafts from a billet. I am pretty sure most if not all crank shafts are cast from what ever material (nodular iron, steel or some alloy) then forged and/or machined after they are cast. You may be able to buy a crank shaft cut from a billet but it would be way expensive.

If I am wrong someone please let me know.

[70blackfish]

i know what billet means, and i never asked if it was a billet crank,

[BB72CHEVKT]

no

[jocko]

it looks like a cast parting line on the counterweight (i.e. thinner than a forged one) - but like Livrat said, very hard to tell in this pic. If you were to take a pic from the front - showing the part Livrat highlighted, you might get a more definitive answer. Also, pretty sure factory cranks for trucks are cast - is this yoru stock motor out of the 69? Forged was usually high-end stuff for the high-end musclecars, etc.

[70blackfish]

i bought this motor not knowing much about it. from a friend of a friend. deal...
he didnt know it was a 4 bolt main and also didnt know about the little rust spot. im not if i should just run it this way....

[jocko]

it looks like it at least needs to be honed, if not bored. Do you have the casting numbers off the rear driver's side of the block?

[70blackfish]

3970010 casting numbers

[bubbaj]

Look on the end of the crankshaft where the flywheel mounts if there is a notch cut in the flange it is a steel crank
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[MusicMan70]

Here are the crank numbers from my 70 350 and I believe the cank is crass or the crank is cast steel