Fwiw, regarding the BB templates....., I had a member here send me a set of stage v heads he template ported using the stage v specific templates. He also cleaned up the entire runner a bit. These heads also had 2.14/1.81 valves installed. The result was probably the most time intensive set of 245cfm big block heads around.
A decent basic bowl blend and valve job, with some very minor short turn blending will get a set of 346/902/452 heads into the 260 range for a fraction of the time investment.
Without some reworking of the short turn, you're only going to get so much flow out of those heads....... And frankly, that's not going to be a very big number.
On the other hand, the templates will keep you from taking too much out of an area you shouldn't.