How do you prime the oil pump?
I would consider removing distributor and hand priming. A 5/16" hex 14" long gets just above the LA/MA block. Many use a drill but I have had good success with only a speed handle. This will save overworking the starter motor. To get oil up to the rocker shafts on an LA move the balancer TDC mark to approx. 10+2 o'clock you should here a squirt when it's at the right spot.
Sorry fellas. If moderator would remove, that would be ok.