Installing rear main bearing seal 273

You don't cut or clip anything with the lip seal. The lip seal goes in the block with the lip facing the crankcase. Make sure there's no oil or grease (even from your fingers) on the seal bores or anywhere but on the lip of the seal. I use grease there myself rather than oil that can seap into the other areas before you fire it, and cause a leak down the rod. Then use RTV at the mating surfaces of the seal, and the grroves in the block under the cap.
Personally, unless this is a race car, you can't go wrong with a rope seal. And those you do clip...