vonkluver - That CPP kit you mentioned is for 1928 Chevy Car and 1/2 ton trucks only, It will not fit your larger 3/4 ton truck.
There are a number of sellers offering 1947-59 Chevy/GMC 3600 (3/4 ton) and 3800 (1 ton) 8 lug front disc brake conversion kits currently. A quick web search can point you towards those options.
I suggest this as a possible alternative as a check of Chevrolet Master Parts Books indicates your 1946 3600 shared the same spindles, inner and outer wheel bearings and steering arms a the 1947- 52 3600 and 3800 trucks.
There was a change in 1953, but since these kits are listed as fitting the earlier 1947-52 trucks, they must have some work around to allow the kits to fit both spindle designs.
Best thing may be to call some of the vendors offering these kits to see if they can be fitted to your '46, or you could replicate Wayne's process and create your own front disc brakes.
