I wonder how come when I ordered a 85 countershaft, it came as the 88/89 part? I called and I was told that the part number superceded. Also, 85 and 86 had different kickers gears, the 86 gears being stronger. I had to replace 3 sets of 85 kicker gears, they tend to slip when compression is raised and used alot. The whole thing about the copression is wrong, 85 and 86 atc's had the highest compression(they used thinner head gaskets). 86-88 were the same compression and 89 had even lower compression(to ease the starting).