Yes it will work! The thing for you to know is there were no major internal changes made to these engines in the entire run from 1960-74.
GMC thrived on interchangeability on these engines. The biggest change was done in 1973 when the 478 got a bigger main journal crankshaft making it impossible to use an earlier crank only on 73-74 478 engines, yet you could turn down the 73-74 crank journals and use that crank in earlier blocks, in fact that's what I did with my 478.
