408 with stock rods?

Yes, you can use them and many did when stroker cranks were first introduced but because the cost of refurbishing an OEM set of rods was just shy of new aftermarket rods, the OEMs were getting tossed in favor of the new ones. As 70 mentioned, you will need to clearance the bottom of the bores for the rod bolts. This goes for some of the aftermarket setups as well (depending on which rod bots are used).