I've been searching for 3 days and can't find out what exactly 6.0l engine I have. Any help would be greatly appreciated! C31396066

 

Look at the VIN on the dash, pretty sure that a 8th digit U is a LQ4 and N is a LQ9.

 

Can't, it's a 55 chevy truck, and the engine was built by a guy that passed away. It's a 6.0l of something, but the numbers are dot stamped and don't cross reference to anything I can find.

 

Look at the pistons then. Dished pistons are LQ4 and flat top are LQ9 if I remember right.

And the heads too, the old ones come with 317's and I think the LQ9's have 243's, but maybe not all.

 

No lq9 didnt have 243s

 

Gen iv 6.0s will have iv 6.0 cast into the block, gen 3just has 6.0 cast intonit, gen 3 flat tops were typically lq9 dished were mostly lq4, have seen a few supposed lq9's, by vin and rpo that had dished pistons and pressed rods....biggest difference between the lq4/9 is the flat top pistons and floating rods on the lq9 and pressed wrist pins and dished pistons on the lq4... Blocks and cranks are same heads were mostly 317s....though inthink there was another casting number they may have used...

 

Also forgetting that in late 04 the lq4 recieved same rods as the lq9 and other motors did

The difference during that era was .5 in cr by the piston

All iron 01-07 gen3 6.0 had 317s..99-00 had iron heads and weaker motors that had a odd ball crank

 

The early crank was designed specifically for the 4l80e to bolt to....

 

There was an 035 replacement head floating around for the 317's

Grippy had a set on his old ride.