What you'll find on these trucks it that there is a huge amount of variation from one to the next. It results in somebody not having to touch the firewall with a BB and 2" of body lift, but the next truck might have to scallop the firewall in 3" with the same lift kit. No way to know until you do it. On my Blazer, I used a 3" body lift when I installed my 496 with tall valve covers and I had to cut & weld in large patch panels to clear the covers. The distributor was clear by a mile though. If you're able to do little body work, the mods are relatively simple and look really clean when done
.