Yes thank you for the good info. I was aware of the heads but not the crank problem..

 

Seems you were warned while you had the engine out.Did you not take the groups advise seriously?

I just had to ask.

 

Parish8 saved me Much time and $$ by noticing this on the engine I bought and subsequently returned. Thanks !!!!!

 

That's a good pic to post...I guess that's the difference in the "long crank" and "short crank" blocks. It would be nice if someone has a pic of a 99-00 6.0 block for a comparison. I guess if someone was swapping in an earlier block with a 4L80E they'd be good to go (aside from adapting the 80E to fit of course). Glad I was able to find an 03 LQ9 for mine

 

BAD CRANK!! Or at least the long one.





GOOD CRANK...the shorter one, picture below

 

Perfect Isn't there a tech info sticky we could link this to? Very good info here that could save some folks time and money.

*EDIT* got it: https://www.performancetrucks.net/fo...=1#post3207041

 

So, if I understand this correctly:

If mating the 6.0 to a 4L60e, use the flush crank
If mating the 6.0 to a 4L80e, use the 'stick-out' crank

Is this correct for best results?

 

I *think* that to mate it to the 60E you need either the flush crank (or a custom tq converter if it's the 99-00), but if you're going to the 80E, either will work but the 01 and up blocks will require a crank spacer.

 

th350 and th400 will mount fine to the "long crank" where with the "short crank" you need the spacer

 

The article "Gen III GM Small Block" by Doug Anderson reports the following.

"All of the 99-00 cranks had the 12552215 casting with the wide flange. This is the only application for a crank that has a 92mm stroke and a wide flange.

All of the 01-04 cranks used the 12552216 casting with the narrow flange, just like the 5.3L and 5.7L, but the 6.0 pistons weighed considerably more (470 grams) than the ones used in the 5.3L and 5.7L engines, so the bobweights had to be dirrerent. These may even be two different versions of this crank because the rods used in the LQ9 motors weighed 36 grams more than the ones in the LQ4 motors."

Then on another page is says:

"Thre have been two heads used on the regular 6.0L engine along with a third one that was used only on the engines designes to run on natural gas.

The cast iron head on the 99-01 engines was a 12561873 casting.

All of the 01-04 6.0L engines had an aluminum head with a 1256317 or 12572035 casting. These heads were used on all the 6.0L motors including the standard LQ4 and the LQ9 performance motor. They're easy to recognize because they have the same "DEE" shaped exhaust ports that were found on the LS6 heads.

All of the 6.0L heads have 71cc chambers."

Hope is is useful.

Jim