Ok. Sounds good. Ive had a 1uz, 1ggte and currently working on a 3rz all with w58 boxes and g-series.The 3rz conversion is unfortunately not progressing very quickly at the moment. Not sure exactly what weight the 3uz will be, but from my experience, you will be looking at a minimum of 150kg extra weight. But you wil find the balance will be similar to a standard AE86. From memory, the 1ggte/W58/G series added 5% more weight over the front axle, while the 1uz/W58/G series was interestingly 3% more weight over the front axle only. This was because the V8 can be mounted further back. I remember this because it was a major factor in getting the cars engineered.

The links were in the old toyomods site with pics.

Here are some more

I remember on the 1ggte/W58/g series I used an MA61 strut, MS65 hub and used the MA70 front and rear brakes complete with master cylinder. Just needed to make an adapter for the front caliper. The engineer loved it because it was a complete brake system. It also allowed me to use EL, EF falcon wheels. But it took quite a bit of fiddling with the backing plates for the rear discs.