rmillburn ... I tried removing the upper seal from a gmc 270. I got one of those sneaky pete tools that screws into the old seal. It wouldn't budge. I then loosened up the journals that support the crank, and it still wouldn't budge. It was then I decided to pull the engine, and do it on a bench.
Look for the sneaky pete tool first. They also have a "Chinese Finger" tool for getting the seal back in.
You Chevy guys are lucky. I don't think there is a neoprene seal that will fit the jimmy engines
