Those mounts go between the bell housing and frame cross member, not connected directly to the transmissions. I believe the difference lies with the bell housings and cross member mounts. Below are screenshots from the 1948-51 Shop Manual and 1954 Shop Manual that show the two different mount designs.
Can you post a picture of your bell housing at the mount points as that should help clear up which style mounts you need?
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
