You can;t just spin it and stick it back in. When it is idling rough turn it in it's place (c-wise and ac wise), using the adjustment screws (or not). Whilst turning it you will find one way will yield a better idle this will tell you how far off you are and what direction to reset the dizzy shaft to.

Have you got the manual?

There is a section in there for timing etc.

EDIT
Take the tappet cover off, manually turn the engine over (take out the plugs for easier spinning). Turn it until you see cylinder one 'on the rock' where it has completed it's intake stroke and it is at the end of the compression stroke - the position of the valves will be an indication of what stroke it is at.

The rotor on the distributor should be contacting the lead for cylinder one, using your firing order (is it 1342 or 1432? double check) put the right leads to the right cylinder.

When this is all done you can fine tune by using the adjustment on the dizzy.

If this fails check that all spark leads are getting power, while you are at it clean all the contacts (rotor end/button, distributor cap buttons & the point inside/underneath the rotor).