I have 88gt, I am not sure if the engine in there is 88 or not. I disassembled the engine and the pistons in there are flat top with no notches cut out for the valves. I am looking for a rebuild kit and there are 2 different ones 86-88 and 89-93. What's the difference between the 2? My last engine that I rebuilt was 89 and pistons had notches cut out for valves, but this one doesn't. is this normal for factory 88 engine? My plans are to replace rings/bearings, gaskets, pretty much stock rebuild.