Outlet adapter. I have the 2560s(600) and if I had to do it again I would choose the 700. I did 477whp on the 600 with forged internals and SZ OTC chip, with a flat torque curve of 415wtq. A friend of mine on stock longblock did the same with much more torque. When he did the race fuel the difference was about 75/80whp compared to the 600 on race fuel. The major difference in torque is said to be that the 700s spool faster than the 600. Hell, the 700s with breather mods spools as fast as the 530s but pass 4500 rpm will blow them away. Get the adapter kit from CZP not from ash, if you want them before 2017.