Quarter Mile Gear Selection

This note is probably late, cause the o.p. has already said he's going with the 4.10, but.....
The case break is at 4.10/4.56
If you have a 4.56 carrier, you are stuck with 4.56 on up (4.56, 4.88, 5.14, etc)
If you have the 4.10 carrier, you can use Dr. Diffs 3.23, 3.54, 3.73 (no 3.91s for a dana that I know of) and 4.10s, AND! you can get thick 4.56 or 4.88 to use with the 4.10 down carrier.
So, for maximum versatility and gear choice, the 4.10 down carrier is a no-brainer.