The new rope that is out is nothing like the old seals. I gave up any rope other then from BEST GASKET. They came up with a really good replacement that requires no packing.
For a rope to seal, it must be bigger then the area its going to seal, then get compressed into place. The old stuff could handle being pulled into the seal groove then packed in with a special tool. This new stuff just falls apart. I slightly packed a seal from Best and locked the engine up solid after a break-in. Once cooled down, it ran till it heated up again. I had to replace the seal and follow directions to the letter.

Have you checked your bearing clearance since you have it apart? No seal will work if the crank is bouncing around.

Good luck, and keep us posted.
Joe

1937 Chevrolet Inline-powered Streetrod