Mid 80\'s Engine questions What year did chevy go to the center bolt valve covers? Also when did they go to the serpentine belt setup? Is there any easy way(without yanking and disassembling) to check the block to see if this stuff was added to an older block. I am contemplating an auto to stick swap (TH700 to SM465) and I am reading that somewhere in the mid 80's chevy changed to balancing externally. What year did this happen? I am much more familar with Chevys of the 70's where everything was pretty much interchangeable. I had done this swap on a 77 K10 with no problems, so I am just curious what to look for on the flexplate as far as weights. The more I dig in to my 85 K5 project, the more it seems like a jumble of what someone had laying around.- probably why I got such a clean bodied truck so cheap.