Yeah I said on quas' stream that illaoi is nice into e max nasus and he agreed, you should be able to 2v1 that lane. There's a few items you'll need though: 1. executioner. Nasus is a sustain god, you need some healing reduction, think of it as dealing percent invisible true damage straight to the heals, ouch.
Black cleaver. You need armour shred, you need cool down reduction it's a 2 for 1.
There's a certain way you play most lanes and lane pressure nasus is not much of an exeption: you're weak in a 2v1 early, like really weak you don't have a way to self peel the jungler, you don't have the aoe damage you need pre 6 to get him off, you have nothing.
Now your laning is pretty good, illaoi can bully (and I do bully into hard match ups as a risk/reward thing, you need to survive till you buy all the armour vs trynd for example, pushing him onto tower means he can't harass you while you're under tower) but if you bully your opponent there's a loooooong lane behind you where you can't escape a red buff anyone. Its not worth the risk when you guaranteed get to be able to 2v1 10 cs behind your laner. Just let them push, trimming waves with qs before the wave hits turret.
The last thing you should get is itemising into e max nasus. Get merc treads for a bit of mr, and a chain vest for lee sin and nasus qs. Nasus doesn't do a lot of damage, shut down the little he has and you should be ready to 2v1 top lane.