Have any changes been made to the LQ4 shorblock over it's production life?

 

I believe that the only differences are that the '99-'00 LQ4s had the longer crankshaft and will only mate up to the 4L80E, and in 2005 they got the stronger connecting rods that were in the LQ9.

There might be more, but I think that's it.

 

The con rods is what I thought I had read something about. How big of a deal is that for someone like myself looking to swap to a 6.0? It will be built similiarly to my 5.3 with a little larger cam and 3200 stall, nothing radical.

 

If you use a 2001 and new LQ4 or LQ9 you will just pull the old 5.3 out and drop your 6.0 in. Its that easy.

For model year 2004, the LQ4 got the full floating wrist piston pin design that was introduced with the 2002 LQ9 that uses snap rings to hold the wrist pin in position. This change to full floating pistons helped the LQ4 extend durability beyond its original 200,000mile validation.
These pistons are recontored and feature coated pistons skirts to allow a tighter piston/bore clearance. The coating started MY 2003.

In 2004 or 2005 the LQ4 got the LQ9 rods as well.

peace
Hog

 

Thanks hog. It'll be interesting to see which rods I got, since it's supposed to be a 2004 engine.

 

04.5 up also use different headbolts. 99-04 use 3 different length bolts where as the 04.5+ use 2 diff bolts

 

My '04 shortblock had the LS2 rods, full-floating wrist pins, and coated piston skirts. Got lucky and got all the upgrades.