I just bought an '87 K5 and the oil pressure reads 15 max and drops to about half of that at times. I changed the sender unit thinking this might fix it, but it didn't. Could it be the gauge? The Blazer has 84 K miles on it and runs great. I drove it home about 450 miles and had no problems. It didn't even burn any oil. I think it has more pressure than its showing, but it makes me a little nervous driving it with that low a pressure. Any suggestions?