As requested by owen "do what i ask or its curtains" sparks here is the rundown on what flywheel you can use with either 1mz,5vz or 3vz V6's.
1mz-fe stock manual steel fly will bolt straight on,no machining,mk2 na or T starter motor works without a spacer.
3vz-fe stock manual steel fly will also work as above,no mods needed
3vze 4runner stock manual fly fits the crank bolt pattern exactly but its offset and thickness are wrong so machining is needed to both front and rear face to make it work.This machining basically means copying the dimensions of a stock 3s-gte flywheel which is 30mm thick and its back face sits 5mm from the engine block face as an offset guide.However the ring gear on this fly isnt in the right place and you need a 6mm spacer between starter and gearbox casing to as jean-luc picard would say "make it so" :D
There is also a 1mz-fe aluminium fidanza fly that JB is using,this works exactly like the stock 1mz/3vz wheel.
Ive no data (another trekkie ref) for the 5vz manual fly working on a 1mz/3vz but i do know that node from mr2oc used a 3vz-fe manual fly on his 5vz,so this means a manual 5vz fly (if they exist!) will also work on a 1mz/3vz.
All of the above flys except the fidanza are available stateside for around $20,but the shipping is a bitch at around $70-$90.
If anyone has some good info they can add please do.