I am not aware of any dropped spindles for TF trucks. The ones I have seen are for cars which are completely different. There are dropped axles available however. I suggest that you try to locate a complete front axle from someone that has converted to an independent suspension. That way you can get all the parts you need. You will more than likely have to replace the king pins regardless of what you find.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine