Originally Posted by C|3R1C
I'm pretty sure you can go straight up like that, from 535 to 650. Off the top of my head, you just have to add the intercooler, tune, and new pulley for the blower.
I believe you need larger injectors as well. I upgraded from the 575 to the 600 and wish I would have gone big from the start. If it fits within your budget, get the 625 or 650 right off the bat and save the hassle and additional incremental expense of upgrading.