im going to forged my '06 silverado iron 5.3l block and i want to know if i can bore it out to a 4.000 bore or whats the biggest i can go with my stock block i have a turbo set-up on my eng. and thanks for the info

 

bore it to an ls1 bore which is like 3.898-3.905 4.000 never gonna happen buy a 6.0 for that

 

yeah, i have heard of people taking the 4.8/5.3 blocks out to 4.00 but not sure how well they would hold up on a street truck. Id go 3.905, and use a 4in stroke crank and build a 383. This is what im building for my Sonoma GT project, using 243 heads and truck manifolds for a single turbo setup.