I don't have a MSD system, it's merely an aftermarket distributor from a speed shop, the brand I don't recall.
The only logical access is from above. I've spent much time contorting myself in the engine compartment, but use pillows and blankets to make a resting place. This is the first time that I wasn't running a Holly when the distributor quit on me. After owning the car for 41 years I've spent much time nesting on the transmission. The Webers have me back there regularly, but they look so cool and perform very well when they want to. It's worth the hassle. I bought the car with Webers raced by Hugh Kleinpeter, but bought a more streetable set last year.