What is the silver box attached to the firewall with the three hoses coming out of it? By the way, this is NOT my car.

It's a crankcase breather system meant for use with carbs.

The previous owner has installed a Megasquirt system and I have no carbs. Is this piece still necessary? It seems to have oil running through it. Stumped...

It takes the place of the pcv system that is part of the stock fi.

I assume both lines out the sides are going to the ports in the heads?

Probably would be better to plug the ports at the heads and run just the one from the tower to the middle port on the box, the reason being that the tower is meant to be an outlet, the ones at the heads, inlets. Without any help (plumbed to the air fliter[s]), they all end up as outlets. This would be debate-able of course.

You still want your crankcase to breath right? Two of the hoses come from the head and one from the crankcase itself next to the distributor. It should just be oil mist, anything more would be... disconcerting.

Are you going crank fired? If so, Original Customs has a better solution. Plug the heads and use this...

Caution though, you must allow the crankcase to breath. Plugging it up will blow seals out.

If you have fuel injection (EFI, electronic fuel injection which MS certainly is), then you would vent to the air cleaner housing like the factory EFI system. Your heads should have litte tubes sticking out of the heads, you should be able to see the tubes looking in the engine compartment; and hoses from these tubes should go to an "anti-flashback" valve/connector then a hose to the filter housing. If you still need help finding the vents, search "Dave Darling hose diagram" or such for a pic. At any rate, you need to have a vent "system" as the case produces positive crankcase pressure and that needs to be vented somehow ...

Thanks everyone. I will probably just leave it alone for now until I get a better idea of what I am doing and how these engines work.