Front shock bolt sizes

Hate to make a new thread for this, but did a search and couldn't come up with anything (found a post where someone was looking for the size, they found it but didn't post it..doh!).

Getting ready to replace the shocks on my rig, don't want to deal with the rusty bolts that mount to the axle up front so I'm just going to cut them off, can anyone tell me what size these bolts should be? Any problem using nylock nuts on there?
Thanks!