brake swap from 1981 G20 van to '68 C10?

[68_GMC_910]

Hey all, I don't know jack about vans so bare in with me here.

My automotive tech teacher says I can get parts off a junked 1981 G20 van for free. at least I think it's a G20. I know it's a "20"... But I'm not sure if they used the "G" prefix that late...?

Well anyway, will these discs be swappable to my '68 910? (a Canadian version of a GMC C10 for those who don't know) I noticed the master cylinder is a good bit bigger on the G20 if that matters... should I and can I swap that along with it ya think?

What about the rear? I didn't check if it has discs or drums in the back but I did notice that it looks like a 10 bolt back there... I didn't count the diff. bolts, I just glanced at the back end from afar... I'll investigate further tomorrow... anyway, can I use anything off the back to make my 12 bolt a 5 lug? probably a pretty dumb question seeing how the brakes and axle shafts and everything's a good bit bigger on the 12 bolt, but it doesn't hurt to ask, right?

There's nothing left of the engine or tranny, (unfortunately) the stickers say it was only a 5 liter/TH350 anyway so it doesn't really matter because I plan on getting at least a 350 and 4 speed anyway. It looks to have had power steering but I don't think I'll be taking any of that with me seeing how it's somewhat damaged and I plan on buying a 1969 C10 with PS for parts anyway.

Thanks for any help. It's all really appreciated. It sure is gonna be fun sneaking those parts on the school bus in a duffle bag. :p