I've now had a look at a factory VT manual for Ecotec - useful sometimes
.
The recommended sealant for the head bolts and upper and lower inlet manifold bolts is Loctite 242. Holden Head Stud Sealer does work though, as I have used that successfully many times (and will do so again). Bear in mind that the bolt tension for a given applied torque is affected by the sealant (acting as a lubricant). You have to work reasonably quickly with 242 as, once installed, it starts to set within a few minutes. The Head Stud Sealer stays sort of gummy.
The head bolts aren't single use but the rocker pedestal bolts are. That may be because they have microencapsulated thread locking compound on them rather than them being torque to yield though.
There's no need to apply sealant to the gasket surfaces but the corners of the valley gaskets definitely do. It may help to use the old sealant as a guide as to where it should be applied. Basically it's a bead at the intersection of the head and block, then fit the valley cover end gaskets (I'm sure there's a proper term but my meaning should be clear) then apply another bead before fitting the inlet manifold gaskets and inlet manifold.
The recommended sealant is Silastic 732 but my favorite is Permatex Ultra Blue.
The head gaskets are "handed" i.e. there are left and right gaskets. It should be in the VRS kit instructions but the arrow shaped cut outs in the gasket point forwards and the LHS has an "L" shaped cutout while the RHS has a simple circular hole just in front of each of them.
You can minimise the amount of coolant that ends up in the sump by working carefully and fully draining the cooling system before removing anything else but it's hard not to get some in there. I wouldn't even start the car without changing the oil but I've seen worse things done than driving a car with some coolant in the oil a few hundred metres (or whatever it is). (Like
no oil for a few blocks, cars driven around with leaking head gaskets for extended periods of time.)
You might like to spend a dollar or two in a DIY car wash bay to get the worst of the dirt off the outside of the engine a day or two before you do the job. It's not essential but it's easier to avoid knocking oily dirt into the engine if the dirt is not on the engine in the first place.
Thinners or acetone with
clean rags (old T-shirts are perfect) are the best solvents. They dissolve any oil to be wiped away but evaporate without leaving a residue. Prepsol is OK but does tend to leave a residue if not wiped dry.