OK guys I have a 03 1500 RC with 5.7 that has 334000 miles on it. Only wrench ever put on it was waterpump change at 200k miles. It now smokes on start up and just doesn't have power it use to have plus it pings like crazy if I don't run 93 octane now. I bought a 6.1 SRT8 engine 06 I think and I want to build the bottom end of the 6.1 install the 260 comp and mildly port my stock 5.7 heads and reuse my 5.7 manifold. I know the 6.1 pistons are flat and 5.7 are crowned so im guessing compression will drop to around 9:1. I have the 6.1 heads but would rather have the smaller runner 5.7 with a good port job to keep runners small and torque up throughout range. Im not building a race engine just a torque engine. I plan to use my stock ECM as well. Anybody see any issues with my thinking here? 6.1 block is already at machine shop. Also would a set of headers be worth the effort and are they prone to leaking. Im too old now for the loud exhaust stuff. Thanks