you won't find much for 3/4T trucks -
1/2T disc kit - I'd look for a hydrovac and go thru the brakes - I had a 1.5T 46 and the stock brakes with the hydrovac unit would paste ya to the windscreen - I also considered putting a V8 in it, but there's enough mods necessary I decided against it - might look at bigger 6's like a 261, even a late 235 [around 1960]
Bill