I have had my car for more than 10 years. It is a 440 with a ?(built)? 727. It has a manual reverse valve body and a B&M cable shifter,(no manual kickdown rod), as it was built for doing some racing. I never had any trouble with it except 5 years ago, excessive heat from the headers melted the plastic off the cable housing and the cable popped out. I drove home in 2nd gear at low speed. I put a heat shield around the new cable. I also added a deep sump pan around then as well which added approx. 4 quarts more fluid. It always used to "grab" the next gear when shifting between gears. Never had a problem and usually go easy on it except for those occasional "spirited" launches. Yesterday, I took it out for the first time in 6 weeks and noted when it shifted from 2nd to 3rd, it kind of slid in instead of grabbing like it used to. Once in gear it was fine like it always was. By the time I got home, it started to do a similar slush type engagement in first to second as well. Then when backing up to park it. it didn't want to engage for several seconds. I tried it again into 1st & then reverse and it took some time to engage. The fluid is clean, probably only about 1500 miles on it and no leaks except a drip or two. I do not know what converter is in it either. I am thinking maybe the filter is dirty limiting pressure build up. It is also possible that the threaded adjustment on the cable came loose and moved somewhat. Because it's not stock, where would you first look for the problem? Any help would be greatly appreciated; up to and including a free replacement trans that installs itself! Thanks.........