I've a 1300 x/flow, light weight flywheel, 1300 sport 4 speed box, I want to fit a pre-engaged starter, I've tried a sierra one, it fits the hole but not long enough to reach the flywheel, I've tried another from a front wheel drive 1600 escort, but far to small, help needed to know what starter to fit....

Not sure if I'm talking crap..... the flywheel is designed for specific starter. i.e. parallel teeth for pre-engaged and a lead in for the inertia starter.
There is also a different number of teeth involved.
So... as i write i am thinking.. perhaps you can interchange..... and then perhaps you cant.... I have both types of starters in my garage, i will measure both for you if that helps?
Cheers...

Many thanks,