I disassembled the rest of my 85 GN engine last night that has about 130K miles on it. I found the con rods and caps were stamped with letters indicating a rebuild. Ok, no big deal. Took a look a the rod bearings and noticed that they (Michigan 77s)had 8 87 stamped in it. I'm guessing that's the mfg date, right? The timing chain has the typical GM numbers on it and it looks like the pistons are stock. Could this have been an engine rebuilt by the dealer a year or two later? Also, is the cam and crank journal specs the same as an 87 GN?