Just curious.. why a 340 spec cam? Everything the OEM does/did is done with compromises.... lowest cost to build with acceptable power and/or efficiency... have someone spec a better cam.. BTW.. i put .028 compressed thickness head gaskets in my 318, every little bit helps.
P.S. i personally, for a first car would do a bone stock 318 for him... a 16 year old doesn't need more power til they learn to be safe :)