Truck: 94 chevy blazer 4.3 vin W

So when I bought the truck I ended up pay for a complete rebuild on the engine. So its been around 80,000 miles and I've noticed that the rear main seal is leaking, and also the seal behind where the fan is (not sure on the name of this seal)

I baby this truck oil is changed every 3000 miles. I do not spin the tires or hot rod my truck, nor do I ever take it off roading.

Could I replace this myself?


My question is this normal for these seals to go this early?

I also know that money is tight for me and I really do not need to be spending any money on getting seals replaced right now Unless this is necessary.



And my last question is how detrimental is this to my motor. If I make sure that my oil is topped up at all times can I make it another 6 months to a year with out muffin up the motor?