I'm doing a similar swap with an LQ9. I know S&P headers provide some specific for this swap. I've heard of people using BRP headers, Pacesetter fbody headers, Hooker block huggers, and I'm looking into some edelbrock headers. I'm either keeping my 350 trans or swapping to a 700 though. I've read about some transmissions having clearance issues with some of the header combos but not sure about the T56 in particular.