88 Pulsar CA18 timing?
 

I replaced head (CA18DE) on a free 88 Pulsar given to me. It was partially disasembled, so how do I fasten the crankshaft position sensor so it will be close to where it will start the engine?
Does it only go on in one position due to the shaft spline?

Also, how can I judge the correct tension on the timing belt before tightening the tension roller?

The Chilton repair book is worthless!