Kevin,
Absolutely nothing wrong with running what you choose for "your" truck!
Your truck having 5 lugs all around just means it was modified from the original "6-lug" design before you got it. It's actually a fairly common conversion. When the passenger car "5-lug" rear axle was installed, the PO (Previous Owner) most likely converted the front hubs to the Chevy passenger car "5-lug hubs" to match everything up (a common change*).
* Here is one of many existing threads in Stovebolt about doing a
5-lug front hub conversion. You can find many more conversations on the subject using this
Search the Site link that you will find in the left margin and the top menu bar of Stovebolt web pages. Just click the link and type in the info you want to search and it will provide you a list of links to on-topic posts from the past you can read and learn more from.
I just did a quick web search and found both rear axle shaft and pinion seals for your rear axle readily available from various vendors. Just remember that when you search, you are looking for parts for the 1955-64 "passenger car" rear axle. Truck listings won't match up.
BTW - You can also use the "Search the Site" link above to find previous conversations about what you need for installing an auto transmission. Most if not all of those conversations probably happened in the
HiPo Shop forum. A lot of previous "wisdom" and helpful bits of info in those previous posts!!!
Dan
