The motor/block is exactly the same as the 5.3 dimensionally. You can swap whatever is not on your 5.7 from your 5.3. It all interchanges. Many on here have put the LS1 block in their trucks for more power and less weight. THe transmission is the same except the tailshaft housing has the torque arm bolt pattern for the camaro/firebird, no gain over the truck transmission.