You can replace the rear main without dropping trans. Remove pan and rear main cap. If it's a rope seal, use a "Sneaky Pete" and thread it into rope seal and pull out while turning crank. If it's a hard seal, you can use a drift and carefully tap one side into block while the other side pokes out. Grab and pull while tapping other side. Rope seal can be pulled in with 'ol Pete. If your life depended on it, it can be done on your back with trans in car. All oil will drip to lowest point. Mark base and pull distributor out, it doesnt turn when removed like a Chevy. Replace gasket and drop back in. Line up marks and tighten. Simple.
