generally you can roughly assume he'll be within a similar weight range of the two breeds. Get him weighed to know his exact weight. The growth spurt you're hearing about is usually filling out.
The more people I meet and talk to,the more I love my dogs and their intelligence.
Shasta GSD 5/5/10 CGC
"Dax" Thor z vom Weberhaus 3/18/2013
Zena GSD 6/1/03
Riley GSD/BC 1/10/05-2/1/2013