Outer Limits 4x4 Board

I have graphed the details of my Bundera's transmission

1st Gear 2nd Gear 3rd Gear 4th Gear 5th Gear Diff Transfr
3.9280 2.3330 1.4510 1.0000 0.8510 4.56 2.276

Final drive in High
17.9117 10.6385 6.6166 4.5600 3.8806

Final drive in Low
40.7670 24.2132 15.0593 10.3786 8.8322

I want to modify the gear ratios as I will be replacing the G52 with an R150. I need to learn how peak torque and power is affected by these ratios. How tall is too tall for 5th gear on the highway
How short is too short when crawling in 1st or 2nd in the bush

Also what is the relative ratios for 31 and 33 inch tyres for working out adjusted RPM's on the motor, I realise that with this figure peak power and torque can be worked out for a given gear

If am incorrect with any of these details please don't be too hard on me

Assistance of any kind will be most appreciated

cheers

Bundy_harry

Whooosh... is the sound I first heard when I read this, straight over the head
If it helps... I quickly worked out 31-33 or 790-840mm tyres would be like an extra gear approx 0.94