rotary emotions

I bought a S5 TII to swap into my 1st gen (1982 model, specs as in sig)
Of course I know that the gearbox to go with would be a TII one. However, this would give some really difficult problems: the price would be one thing, the fact that a custom drive shaft seems impossible to get made in Belgium is another.
Since I have several 1st gen boxes (three right now) I'd like to install the engine using a first gen box (all are FB models) and get it running. If the box doesn't last at all, I can still swap in a TII box.
However, I'm in need of some info on the flywheel choice here. To get a TII mated to an older NA box I will need a smaller flywheel, but which one?
I've been told same series can be used, in other words, S4 NA on S4 TII and S5 NA on S5 TII. But not S4 on S5.
So I looked at the flywheel chart at Mazdatrix site. Here the wheight of all flywheels is listed, and it seems the S4 NA comes very close to the S5 TII (1lbs difference) whereas there is way more difference between S5 NA and S5 TII.
Can anybody tell me which flywheel to use here? If I'm going S4 NA (1986-87) I can use the flywheel I have left from a scrapped FC. If I need a S5 NA (88-89) I need to buy one, probable new, as S5 NA were never imported officialy (some grey imports) in Europe.
I won't go for a lightwheight one, as I do plan a TII box in the future.

Metallic_rock

The T 2 I helped IoTus install in his 1st gen used a 1st gen tranny. Just make sure your clutch plate fits on the input shaft of the tranny. (he used a GSL-SE tranny, and I don't know if it was any different than the one for the 82, but it shouldnt' be.)

rxseven

You can use a lightweight aftermarket flywheel with it's matching rear counterweight, no problem. On my car there is a racingbeat 17lb steel flywheel (225mm) mated to the s5 t2 motor. You just can't mix and match rotors and front counterweight but you can go to a lighter flywheel.