Which master cylinder-disc conversion????

[dennis111]

I am in the process of converting my 68' to disc brakes. I also wish to replace the original type power brake booster with one from a 3/4 ton. I am confused on which booster to use on my truck.

Should I order a booster for a 68' or one for a 72'? The reason I ask is that there are different ones listed AND I want to be sure it is compatible with my new disc brake master cylinder. I also have heard that the brackets are different between the 2 years--true or false? If so can mine be modded if a 72' booster is needed?

Thanks!