which 3500s came with forged cranks?

[MidnightriderZ24]

in my quest to achieve a couple hundred horse more, i want to know which 3500 has the forged crank? i found a 05 3500 for 350 and i think im gonna pick that up

[Joseph Upson]

in my quest to achieve a couple hundred horse more, i want to know which 3500 has the forged crank? i found a 05 3500 for 350 and i think im gonna pick that up

It's not dependably specific to a 3500 vehicle as we discovered earlier this year when it was thought according to GM that my two engines one from the 04 Malibu and the other from the 05 G6 had cast cranks. They both had steel cranks and this is how you tell;

Remove the balancer bolt and look for this four digit number:7484 the last four digits in the steel crank stock number, 12577484. There is another number stamped on the end of it also but those four digits are the ones you care about. They were on both of my cranks.

The end of the crank snout is where the numbers are, not the bolt. Thought I'd mention that since it's necessary in this day and age to stamp "Not for on road use" on a wheel barrel.

[sharkey]

even a couple hundred more hp on a cast crank shouldnt kill it. everyone here runs a cast crank, i beleve curtis is running a cast crank at 471whp.

[MidnightriderZ24]

thanks, ill check it when i get it apart. my goal is a couple hundred beyond curtis's.

[wasas9]

Interesting.

Paul, those arent the 3500s in Janesville are they?

So if I understand this right, I need to remove the bolt on the harmonic balancer, and read the casting #s perpendicular to the key right?

[Joseph Upson]

Interesting.

Paul, those arent the 3500s in Janesville are they?

So if I understand this right, I need to remove the bolt on the harmonic balancer, and read the casting #s perpendicular to the key right?

Yep, you should see two numbers, one is long the other is 4 digits, if you see 7484 = steel, 8259 = cast, either way these two cranks are stronger than the previous cranks thanks to the additional metal for added stiffness.

[MidnightriderZ24]

Interesting.

Paul, those arent the 3500s in Janesville are they?

So if I understand this right, I need to remove the bolt on the harmonic balancer, and read the casting #s perpendicular to the key right?

why yes steve... ask for jeremy if u need one, i talked him into selling one DIRT cheap...

[wasas9]

why yes steve... ask for jeremy if u need one, i talked him into selling one DIRT cheap...

I just saw the 2 listed on car-part.com


Hehe you little bastard you!

Did he happen to mention how many miles were on those 2 engines?

[rickykline]

anyone have an actual part number for the forged crank from gm?? id rather buy a new one.. whats the fitment issues with the 3400 ?? anyone tried it yet?

[bszopi]

The fitment issues is about an 1/8" slot where each rod end would come in contact with the block. You could grind out the spot on a 3400 block easily enough.

[timg]

So these are forged? With a bit of block clearancing and a new reluctor wheel, would they fit the DOHC? GMPD has them for $321. Thanks.

Tim

[Joseph Upson]

So these are forged? With a bit of block clearancing and a new reluctor wheel, would they fit the DOHC? GMPD has them for $321. Thanks.

Tim

12577484

Double check that price, a few months ago when I was trying to sort out the cast iron or steel crank issue the $300 crank was cast and the $400 crank was steel. Another concern is that the block relief if I remember correctly because it was done for late model V8s also, is also inside the block as well as the side rails making about a 180 degree sweep, not sure if it is because it needs it or because of the method they used to relieve the block.

[Joseph Upson]

I just checked it and it's still $433 at GMPD, that means $500 plus from the dealer.

[rickykline]

so grind a 1/8 inch off the 3400 block and the 3500 cranks falls right in.... same size bearing journals?

[3400-95-Modified]

Yeah and then you need the external trigger to get the timing to work.