Can head gasket for 4agze be replaced with engine in?

Hi guys,
I've noticed white deposits on the underside of the oil cap and am pretty sure the head gaskets gone.

Does anyone know or can confirm whether i can change this with the engine in?
Also, other then the timing/alternator/supercharger belts and gaskets, what else would be a good idea to replace while the head's out?
Thanks, any feedback is appreaciated.

Thanks for that, any tips/things to look out for when doing this?

Haha, never would have thought of that, thanks for the tip.
 
Can anyone confirm that 90916-02157 is the right number for the super charger belt?
Oh and are the 4age 4agze timing belts interchangeable?
 

Thanks again, much appreciated.

Kogashiwa Kai
Just wanted to check before taking any more parts off, can you remove the crank pulley bolt with a rattle gun or do you need a special tool with a breaker bar?
Thanks.

If you remove the drivers side wheel, undo the drivers side engine mount and lower the motor a few 20-30mm, I believe you get a nice clear path to get a breaker bar or rattle gun onto the crank pulley bolt. However, I have never done this myself, so cannot confirm the fine details or process as much as I would like.

You'l definitely have to remove the driver's side mount - it's in the midde of the timing belt!

Toyota Genuine is usually the best head gasket if you aren't pushing the GZE about normal boost levels.
 
The way I removed the crank pulley bolt was soaked it in WD40 overnight, removed the rear inspection port off the transmission, stuck something in between the flywheel teeth and rotate engine until it locks, then get a big breaker bar and crack the bolt.
 
From memory (I'm running stock GZE) the supercharger belt is 5PK 940. I bought a Gates racing one as they are less prone to slipping.
 
Also do the water pump while you are at it. Again Toyota genuine is best as they come with the front and rear halves of the pump, as well as new O-rings where it meets the engine. Most other pumps only come with the front half and a gasket to bolt it to the rear, more of a hassle.
 
I took the head off mine in the engine bay but took me two weekends working at my own leisure, making sure nothing was lost in the process.
 
Once the head is off, inspect your bores and make sure it all looks okay there too.

I didn't think of that, Cometic was recommended to me by my friend/mechanic. I only want to do this ONCE so naturally i'd like to use the best gasket i can find. What about a TRD gasket?