My 71 RR came equiped with 4 wheel manual drums. Although it stops OK, (and by that I mean sorta poor) I was considering adding a power brake booster. I know the way to go would be to do the disc conversion up front and all, but I wanted to leave it all somewhat original. The engine sports a Purple Shaft 284 duration and 484 lift cam. Would I have a vacuum problem and would I really gain anything by adding the booster? I'm sure I would also need the proportioning valve, and I assume I would also need to change my master cylinder. Finally, if I add the booster, could I use the original plate that bolts my manual master cylinder to the firewall, or do I need a new one of those also? Thanks.