Dexter HD Suspension & EZ-Flex Install (long w/ pictures)

I need help with the wet bolt install. I have a huge clamp from my welding buddy but cannot get the bolts to press in flush with the hanger. I am not having a problem pressing the old bolts out. Is there another way to seat the bolts such as using an impact wrench and pulling the bolt in place? I have tried driving the bolt in the last little bit using a sledge hammer and socket but no luck. Any suggestions would be greatly appreciated to finish the job.