I have removed the engine from my sierra as it seized on me. I have dismantled the bottom end and found the oil pick up clogged up. I managed to free the engine up (when I say I, I mean me and two mates

) I have not taken out the oil pump yet, was just wondering whether or not just to change it out to be on the safe side or are there any signs I should look for in the old that would give me an indication as to its state?