My intension of the post was to find out if by driving short trips would cause excessive sludge build up no matter what kind of oil I used. I only mentioned the lifter problem to explain how I found out about the sludge problem. They would clatter when the engine started and quiet down. It has been doing this for a couple of years. I tried different things to get them to quiet down but nothing helped. I would not have replaced them just for this reason but the engine also had another problem. I would have to add anti-freeze about every 250 miles. I suspected a bad head gasket, this is why I tore it down. None of the tests indicated a bad gasket and the engine has never over heated. The Jeep only has 74,000 miles and has been maintained. This is really sad to have these problems. All I know is the lifters were bleeding down and it was using coolant. When I removed the head I couldn't see any evidence that it was burning coolant. The shop that I took the head to told me that they had to shave about .015 off and that there were no cracks. I felt that this was a good time to replace the lifters, they weren't that expensive. Any way the engine runs nice and quiet and as far as the coolant problem I'll have to wait and see. Thanks to all that replied.
Dennis