set the timing statically then strobe time it to get it perfect. remember to unconnect the blue temp sensor on the front of the block, get a mate to hold the revs at 2000 to 2500 rpm and time it off the flywheel viewing hole, get the flywheel mark in the middle of the window. do this by slackening the distributor bolt and turning the distributor gently one way or the other.
it helps to paint the timing marks white with tippex or something cos it makes them easier to see under a strobe light