double drilled flanges?

[Jared]

just got some and im wondering when i take out my old ones do i ahve to reset the preload and all that crap or is it like a straight swap where i unbolt it and bolt the new one in. 

[MagPede]

If you have a solid spacers on your pinions then it'll be a bolt on deal but if you have crush sleeves then you might run into a few problems when you have to retighten it.

[kyle_22r]

i took my truck to my mechanic when i found the 4.38 chunk i bolted into my axle to replace my failed stock gears(i have a '79 truck, and i've heard all early 4x4s used solid spacers, 4.38s were only available '79-80) had a '85-up style bolt pattern on the flange because somebody swapped it into the '90 axle i bought(tried marking where to drill and screwed it up big time ).  we just took it off and put the flange from my old third member on it with an impact wrench.  only problem we ran into was that the nut is so brittle that it would pretty much just chip off when i'd try to stake it with a punch