If your going to have to do all the body work anyway FMX, it may be easier to mount it on the firewall. The older vehicles had large engine bays, you should be able to fit both motor and brakes. If they can do it with a camaro, you can do it with a 48. As for weight issues, I wouldnt worry. The camaro front brakes are generations newer than your cars factory drums. As such, they should provide a lot more stopping power. Under the car design master cylinders just raises questions. What if something hits it, what if the cylinder cracks, what if the reservoir line breaks, wha if... It will probably save you time and hassles to have it under the hood.