Ditto to what Cletis said.
There are some really cool things you can do to a 235 or a 261 that will make the truck run great.
For a good example, check out
Chris Sweet's '51 or talk to Cosmo about his Corvette intake (with dual carbs) on a 235 with a T-5 tranny set up in his '49.
Cool trucks both and excellent examples of what can be done with an ole Stovebolt Six.
See our Links page for vendors who sell performance parts for the sixes. OR ... if you want to keep it original (bless you if you do) there are lots of resources available to you to enable you to do that.
Whatever route you choose will be great. It's cool you are keeping the truck in the family and getting it back on the road.
You're among friends here and there is no bad answer!
John