So I am thinking I want a 6.0 for my car. But I just read an article that said I needed to be careful when selecting an engine.
Reason stated was some had a longer crankshaft. But I can't find anything to tell me what to avoid other than "iron headed" 6.0.
Now I did find an article that said all iron headed 6.0 were backed by the 4L80.
So is there a specific year/years? Style of truck or van? A vin letter code?
I ask because most of the engines I have found are no longer attached to the transmission.
Just so you know I plan on running a 200R4.

 

99-2000 Had iron heads with a long crank. 01 and up had aluminum 317 heads with short crank. 02 is when the Lq9 came out with higher compression due to flat top pistons. Lq4 had dished pistons. Lq4 and Lq9 have the same heads. I believe in 05 they got Ls2 connecting rods. If the motor was in a 2500 it should of have had a 4l80e. If it came out of a 1500 it should of had a 4l65e or 4l70e.

 

Wow. Great summary. So it looks like 02-09 may be the most desirable LQ9. When did GM put DOD on the LQ4/LQ9? The L92 got it in 2010

 

The 07 classic was the last to get the Lq4 and Lq9 which never got DOD. The 07 NBS trucks got the L76 and LY6 which were the new 6.0's. with rectangular port heads.

 

Thanks. That tell me where to look.

 

the longer crank was to bolt up to the nv4500 tran's before they cast a new bell housing. you can you it with with a spacer to bolt up any ls style trans or it'll bolt to any small block chevy trans without a spacer. I wouldn't run the the iron heads though myself. it's not really a motor you need to stay away from if you found a deal i'd just factor in a head swap.99-2000 I heard rumors early 01's had it to but haven't seen any.

 

Very good i thread.