89 240 Timing question about distributor and oil pump

[GringoEJS]

OK, car ran fine until coolant leak in front cover. I took off the dist. and oil pump when I removed the front cover, and now that I reassembled everything, timing is off about 30 degrees. Seems that gear driven thing from the oil pump to the dist is responsible. Has anyone had this problem? Can I get the timing right without having to drop the oil pump and turning that thingy? Seems it would be a lot of guesswork doing it that away. I tried just spinning the dist. but the half moon at the sprocket keeps me from the easy adjustment. (I hope ya'll understand this) Thanks