Though it is really nice to keep things uniform, I do not believe it is really worth the price. I have one on my 70 mustang because I wanted to change from points but with the 5.0 HOs, I wouldn't bother and I have the same setup as you on my 5.0. You are better off putting the 250 bucks elseware and get more power like roller rockers, underdrive pullies, headers or something if you are looking for more efficiency. The MSD distributor is probably the last thing I recommend changing if your stock one is working fine.
Kevin