Thanks for the info. I'm rebuilding an engine that came from a boneyard, I thought it was a '74, but according to Muzza's site, the serial number makes it a '76 T500A. I'm pretty sure the seals are OK, but the crankcase was filled with water when I got the engine (was sitting outside with no plugs) and am not sure how long they will hold up. I also have the original crank from a '68 engine that came on the bike. Considering the cost of having the seals replaced (see my other posts further down), I'm planning on postponing replacing the seals for the time being, and send out the '68 crank later this year, and swap them next winter. Everything appears to be the same dimensions, I didn't want to find out after I spent the cash on having the seals replaced that they moved the oil holes on the outside bearings or something of that nature. Thanks again for the help.