Desperate help reagarding oils for rangie and other bits

[British Bulldog]

Hey Guys,
This is driving me mental I have a couple of questions. I got the new rangie home today and it is brilliant. I am in love with it. I decided that I would do a full service drop all the fluids and renew the ignition bits and pieces. I went to Supercrap first they had no info books and no parts so went over to Repco. This is where the confusion starts. I got Penrite gas oil 20w-60 as the rangie runs on straight gas, that's a no brainer. The gearbox is the LT77 5 speed so I got two one litre bottle of Castrol Syntrans as I have read here and outerlimts is suppose to be great for these rover gearboxes. But is this going to be enough as Haynes manual says it needs 2.6L and the guy at Repco said 2.1??????
Now for the transfer case he said I can use Castrol EPX 80W/90 as well as for the front and rear diffs. Is this correct as it says on the bottle it is for GL5 but the Haynes manual says the transfer and diffs need GL4. Also if I put syntrans in the gearbox will it mix with whats in the transfer or not? I think I should be using VMX80 instead for the diffs and transfer. As I really don't want to have to put 2.1L's of syntrans in the gearbox and a further 3.1L's in the transfer of syntrans because that would cost $300 and that's a lot of money for oil. I have already spent $600 on doing this major service. As you can see I am confused as all hell what do I do? I have spent hours trolling through hundreds of posts all over the net reagding this and I still get more and more confused. Please help me before I go insane!

Also this Rangie has a straight gas, Gas Reaserch system I was just wondering weeather if the vaccum advance should be connected or not. As at present its not connected.

One last thing is there anyway to lower the seats in a rangie as I am 6' 2" and its hard to drive with a 50% blue world very annoying.

Cheers Kris
Going bald and insane at a rapid rate.

[lokka]

Man your on the right track syntrans or 70 grade gear oil in the LT77 is the go 90 grade gl 4or5 in the transfer and the diffs the engin oil ya got sounds ok as for the vac advance id leave it if its workin and find a gas man who knows his stuff before playin wif it as it sounds like u know SFA about it welcome to rangie world hope ya enjoy
Oh and fill the LT77 till its levelwith the filler bung about 2.7 L and no it wont mix with the transfer oil unless the seals have carked