I think the illness has caused all of us to tweak the plans. I have a 51 3100 as well. I upgraded brakes with dual master cylinder and disc brakes in the front. Seatbelts and I upgraded my tail lights and turn signals so that people can see me at night. Otherwise, I am running a 216 with 3 speed and 3.55 rear end. I think my truck is comfortable for Virginia and I enjoy driving it on nice days. I can do 65 on the highway with traffic.
Figure out what you want to use the truck for.....ie daily driver, shows, Sunday cruiser, etc. that will answer a lot of your ideas and questions. Brakes and seatbelts were a must for me!
My two pennies,
Chris