Double check on the school bus to see if the brake system is compatible with your truck before swapping stuff around...

I don't know the details or if it makes a difference, but I have noticed on many older school busses that they have a dual circuit MC...
But the different part is they have two wheel cylinders per wheel (both on front and rear) and two brake lines running to each wheel. I can imagine that the dual system is setup as a complete redundant system. Probably one half the MC works one wheel cylinder in every wheel, and the other half the other wheel cylinder in every wheel. Unlike the front and rear split dual system we're accustomed to.

Again, the MC and booster might be OK to swap and use as a front and rear dual system, but do some thinking and checking to be sure it'll work like you think.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-