previous owner
 

The previous owner said that there were larger injectors put in the truck before i purchased it, question is can i find out what they are by taking them out and looking at them?(part #, or something?)

Most shops do not stamp #'s on them. About the only way to tell is take them to a shop that can test them and have hole size checked.

When I took mine out they had the number for RV275s on them,but woodsrat is right,there is no way to be sure that I know of,other than take em' out and have them tested.