Camshaft from 71

I have been offered two camshaft from a 71, model, A standard one and a 'S' cam
I believe that the bushings are different from my 72 & that the 71 has the end cam mounted breather
As both cams are in excellent condition I could buy them if they will fit?
What are the differences between the 71 & 72 cams where the breather changed from side to rear
Checking on AN I also note the bushings are different but are the parent bores the same on both years??...
Is this a viable plan in light of the different years/ change if breather??? ... but as the 'S' cam is available it could be a great plan... on paper anyway

Thanks

The scrolls on the bearing surfaces are different on some cams. You might have an oiling problem.