Hi Bill,
It's great to hear your opinions on this stuff. Thanks for chiming in.
I ma going to leave the wheel boxes as is. The 39 inch tires will probably be replaced with something smaller. The 37s I run on the road are the perfect dimensions and do not rub anywhere. This will probably be the next tire, unless I can get my paws on some 900R16 XZLs.
The weight figure I have heard for the 6BT is 960 lbs. This sounds alarming, but considering a Toyota 2H is supposedly about 700 lbs, by moving the batteries (two of them on the CDN market) to the back, the front axle loading should be very similar to the stock HJ60 wagon.
I am planning on using an Eaton H072, which is actually an american axle. It looks very similar to an ENV (ENV engineering was collaborating with Eaton in the 60's, and the design similarities are evident), but it has a hypoid gearset that is probably the strongest ring and pinion setup of any light truck axle in the world. The pinion is only about eight inches long, and is supported at both ends (both behind and ahead of the ring gear) by huge bearings. The pinion shaft is 2" diameter, with a 10 spline pattern borrowed from heavy truck Eaton diffs, which leads me to believe that much of hte design is scaled down from their larger axles. The ratios are very coarse, huge teeth on the ring gear, and the carriers have a load bolt that limits ring gear deflection under high load situations. It's a very nice piece of engineering, and the axleshafts are interchangeable with the Chevrolet 14 bolt rear axle, for which aftermarket alloy shafts are available.
I am having a love/hate relationship with the Toyota axles, the e-locker especially.