Who understands basic concepts of maintenance I sold a '72 K5 to a friend almost a year ago. One thing I told him, watch the fluids (you know, check oil like you would in any older vehicle). I had put a good running 350 in the Blazer before he got it. 2 weeks ago he said that he thought the valves or something were rattling at higher RPMs. I asked him, when did you last check your oil? He didn't know. he hadnt changed it since he got it from me either. I told him to check and change his oil. He never did check it before he left my house. next day he changes it. Including the oil that was in the filter, there was about 1 quart total that drained out. It never did smoke or leak oil or burn it... but in the past when I drove with that motor I had to add some oil once in a while. I listened to the motor after the new oil was in. A definite lower end noise in it's beginning stages. I'm not the greatest maintenance person cause I have so many to keep track of, but Ive never run a motor that low before. It just bugs me that a good motor is ruined by not checking the oil.