well i found out all the specs on my motor. said the rods were shot peened and ground down. doenst shot peened mean to make it harder on the suface? how do they do that? ground down does that mean to lighten them up. ?

Yes it surface hardens the metal. The rough forging flaws on stock rods are stress risers potential places for a crack to start from.

First step is to grind them off even the direction that you grind is important grinding with the beam of rod is way to do it if ground across now thousands of stress risers are created(not good).
Then shot peen the rod.

All this will slightly improve strength of rod.

Not so sure all this is relevent any more with all the cheap billet and forged rods being sold probably can buy a better set for less than reworking stock stuff in most cases.

You are correct. Shot peening is similar to sandblasting. Instead of sand they use steel shot which hardens the metal ...russ

Cool!! Another use for my old 16 guage! LOL

Also good for engine no start conditions ...russ