ddgonzal,
Not sure why Hilux (Toyota G-series) has the wrong stud pattern? aren't 2WD hilux 5x114.3? and 4WD 6x???. BW78 is either 4x114.3 (R31) and other 5x??? axles.

As for decision:
Either way you go the machining work is about the same and nullifies that as a discriminating factor. Although.... It is possible to machine just one BW78 axle to shorten for a 1200. But given you are tubbing with presumably big offset wheels, you will need to shorten both sides.

Everyone can pick up either BW78 (Falcon, Commodore Nissan R31) or a Toyota G series (Land cruiser Prado, Hilux, Hiace, 4 runner etc) for next to nothing, neither come with the right spring perch offset or 4 Link bar offset.
Look at the axle strength option, G series has bigger, thicker axles standard (30 v 28 spline).
The G series is an 8" ring gear, I think BW78 is 7.8" (I think). Not going to worry you.
G series would probably be heavier overall.
Ratios will be important for your application. If you need taller then 3.5:1, you will struggle to get with a G series setup (Very hard to find). short gears are the opposite, harder to get in the BW78, heaps in the G series due to the 4WD range it was brought out in.
LSDs- Stock both are very crap for anything other then mild street and drag racing, on a circuit track both standard diff will not cut the mustard on a mild track worthy car. BW78 has a cone style LSD (Happy to be corrected on this) where as the G series has preloaded clutch plates.
If you go aftermarket LSDs, options available for both. Cusco/Kaaz, Torson, Lokers, Spools etc.
Ratio changes are arguably easier with a G series as the third member is removable, where as the BW78 are attached to the housing. Although the majority of people would not change ratios very often.

Whilst I have a preference for my application, I have tried to keep my bias out of the above detail, it is really up to you both have their advantages.
There are other options too, early Mazda's (with the right aftermarket upgrades can be good), ford 9" or 8" cheaper replacement parts, arguably overkill.

Just leaves me with more decisions!!! Hahaha
Give me your opinions. This car will never see the road as a road car. It will purely be a show and fun car. And yes 10 inch wide with big offset wheels lol

Yeah mate 2wd hilux pattern is 5x114.3.only problem with the Borg Warner depending what gear box your running there hard if not impossible to get the right gears.im running a hilux in my 1200 with a 13b and also running 10" wide rears.was going to run a Borg Warner at 1st but couldn't get the right gears to match my 5speed.so went the hilux instead

Ah I see Datrotor. I think I may just try get a hilux diff then. Sounds like it will work much better with the set up I'm after. Btw I will be running a pp 13b with 51mm idas and a series 4 5 speed box. Just in case you were wondering.

Next task is finding an engineering shop in CAIRNS that will shorten a diff for me and don't try charge an arm and a leg coz they have no idea what they are doing lol

Yeah nice.mines a built,balenced and injected bp turbo.think my diff was around $2200 to get shorten with very strong axles from the USA and all new bearings,seals and custom caliper brackets

Ok for my opinion,
G-series (Hilux), its what I run in my 1200 Race car.
If you are never going to see the road, look to run floater hubs. This is safer for drag/circuit racing and much easier to do as an alternative to shortening. This prevents the wheel coming off when you snap an axle. Can also camber the rear.
http://msfracingcomponents.com.au/fullfloatinghubkits/ is a good start.
If you are drag racing then the standard Toyota LSD should be fine. Bolt in upgrade is a Cusco. Kaaz requires a ring gear spacer to fit. cheaper options (non ramped) are Loka's which would work well for drag racing. or for a cheap option Spool (full, mini, GIC).
Remember when you replace the rear suspension or convert to 4 link, consider how the thing will roll and act under acceleration, braking (anti's - Dive/Squat), there is an art to getting up the rear properly and not just weld 4 equal length rods in and call it a 4 link.

Hope that helps, good luck

Bryan

Theres also a Maddat IRS setup that could be worthwhile for cheap R200 lsd centres
bit of cutting and shutting but worthwhile compared to most 4 link setups out there
http://datsun1200.com/modules/newbb/v ... id=245494#forumpost245494