Another distributor question

While iv been doing this same thing,iv welded and cut my slots.i read somewhere in an article tha a slot of .350 long will give the reccomended advance of 32 dagrees with a 10 degree initial..can anyone verify slot length for the advance desired.Tey seem to be pretty short.Iv seen some pretty good milling machine deals in the bay area,found one for 450..its not a brigeport tho..its a Sharp..but i can live with that.once again thanks for the help...J