So the 40 drums on the front of the model A have seen the end of their life. the drums are cracking and warped. I did some research about 58 buick aluminum drums and realised it was a do-able combo. However i chose a different path as to set up and modification.. I bought a set of drums.. and set about observing all the things i would need to modify..I will try to explain what i did.. they are working fabulously . first off.. most of the post ive seen show mounting the drum behind the hub. since the ford shoes are1.75" and the drum surface is 2.25" I figured if i could just get all of the shoe in contact with the drum it should be enough stopping power.. I chose to keep it simple and keep the 40 brake shoes. (albeit a new set with modern brake linings.) So the first step was removing the 40 drums from the 40 hubs.. the drum is swedged to the lug studs. I cut off the studs flush with the drum . Ground out the swedge then punched all of the studs from the hub removing the drum from the hub. Next the buick drums i purchased came with the buick hubs. i chizzled off the rivets holding the aluminum drum from the hub. They are pretty soft so a sharp chisel and a few solid wacks with a large hammer will do the job. The whole center in the buick drum is larger than the ford hub. and i preferred to mount the drum on the outside of the 40 hub. so i machined a small aluminum concentric ring. so i could center and mount the drum on the hub.