Consider having the heads angle milled where the material removed is on the combustion chamber side of the head.I angle milled my 85cc 346 heads to 78cc and did'nt have to cut the intake or intake side of the head.I could have probably gone farther but the quench dome on my pistons would hit the head.
pick a cam as if it were a 440 and maybe go one size smaller for the 413 depending on the rest of the combo.