Ok, that's probably just an i. You'll have to find the casting number on the block to know if the bottom end is 2.5 or 2.7.
Other than the added-on fuse beside the brake booster, the wiring looks unmolested at a glance. I'd figure out where that wire leads to.
Those 3 blue hoses do not look like anything from the factory that I've ever seen. I would find out where those go ASAP, especially the one that's just open.