6.0 iron block question
#4
The blocks are all the same from 1999 (when the LQ4 was introduced), although early cranks (1999-2000) required a spacer for the flexplate/flywheel. This is of no concern to you since you are building a 408. In 2001 and later models, when the LQ9 was introduced, all 6.0L (less LS2) received the 317 heads standard. Somewhere around 2003 they switched over to one size length (short length) for the cylinder heads, versus the corner two being shorter. You can find the LQ4/LQ9 in 1500HD, 2500/2500HD and 3500/350HD series Vans, SUVs and Trucks, as well as Escalades and Silverado SS's.