Are these hard to remove? I have to send my differential housing to a guy in beloit, will do 3.70 upgrade, plus posi rebuild for $630. I wanted to have this done, and shops charge over 1k because they are removing it. I have a 74 service manual, lost my 76 supplement... Is it the same on a 76 vette as a 74? Doesn't look bad at all, or am I sadly mistaking....