well how can you tell the difference between the 2?

a gm cast crank and a gm nodular iron crank? (this is on a one piece rear main seal, 350, stock)

do they have different part #'s? anyone?

 

don't think you can tell looking at them externally and only with pratice could you tell by looking at a break. nodular is stronger than regular cast.

 

damn. a guy is trying to sell me a crank saying it's nodular. well i don't believe unless i'm absolutetly sure. well i guess i'll pass. that's the reason i want a nodular crank in my little build up, it's a little stronger.

i would have thought that gm would have given it a different part#.? oh well. thanks.

 

might look in a metallurgy book but i think the only way to tell is looking at a cross section fracture. might be able to tell with a spark test and a grinder on a weight, but i doubt they'd let you try that.

 

I'm not sure if chevy used it too, but pontiac V8 nodular cranks where cast with a large N on one of the throws. You may want to look for this.

 

Speaking of spark testing EDE, what are we looking for? If you grind cast iron it throws a spark. But cast steel doesnt. Or its the other way around, I always get it mixed up.