Was talking to a buddy this morning on the way to work about truck upgrades. I mentioned replacing the stock turbo with a 64.5. He instead suggested doing a sequential setup instead. Keeping the stock turbo and adding a bigger one while eliminating any lag at all. More horse and more torque. My question is how big should I go? I had wanted to add bigger injectors as well. Would I be able to add a 75mm turbo, then have 125's or 180's? I know I'll probably need a lift pump, so I was thinking the fass titanium series. What size would I need? Do I need a different cp3 or duals or is the stock good enough (which I doubt)? Would the regular 425 head studs be fine or would I need the 625's? Does it need a different manifold? Such as a modified second gen? Would any of the motor parts need replaced for the added power such as the push rods, connecting rods, or pistons? I'm giving this a lot of thought, hence the number of questions. Would a racing cam or heads be required? I would appreciate the advice. Thank you for your time?