Trouble installing distributor
 

Trying to install a new distributor in an 86 F150 302. The problem is the shaft for the oil pump won't stay centered and I can't get the shaft on the dist. to mate up with it. Are there any tricks to do this? I really don't want to remove the oil pan. I've jiggled the dist. every which way just trying to get it in. Everytime I re center the oil pump shaft, it just flops back over to the side.