8-lug brake upgrades?

[Steve@OldSub.com]

I'm using the IFS from a '72 C20 under a '54 GMC 1-ton project. The '72 has 12.5 inch disk and the C20 and C30 part numbers for brakes are all the same so I'm comfortable this stuff is up to the job.

But never being completely satisfied I looked at the parts available for an '87 and discovered the rotors are 12.875, fully 3/8ths larger in diameter.

So I have two questions: First does anyone think that 3/8ths inch would make a real difference? Second how easy is it to upgrade my '72 IFS to the later larger brakes?

And a third question, is there some other 8-lug brake upgrade that makes sense? I don't mind going out and finding a later IFS crossmember is that is the right way to approach this. I doubt it would cost even $100 to find a later one and I'd rather upgrade before I start spending money rebuilding the early IFS.

But if there isn't really any difference I'd rather stick with what I have and keep building rather than look for more parts and more work.

Thoughts?