2 things I don't get #1 = why do I need a convertor box for my rallye dash tach to work if I install MSD 6AL and pro billet distributor? I have the orange box and regular vac adv dist now and no need for a special convertor box.
#2 = 734406pk, you're saying that if I have a vac adv dist then no need for MSD box...but I need the orange box?why? And yes they do make RTR pro billet msd, found it at summit's link.
#1= You need a converter box for your rallye dash tach when using the MSD 6AL, regardless of which distributor you will be using. The tach waveform from the MSD6 AL is different (12 volt square wave with a 20% duty cycle) from what the rallye tach is designed to read for RPM when using the MOPAR orange box.
#2= If you want an MSD pro billet distributor with a vacuum advance, you will need to get the RTR model:https://www.summitracing.com/parts/msd-8387/media/instructions
This distributor does not require the MSD 6AL to work, it has an internal ignition amplifier inside the distributor. A MSD 6AL can be connected to it if you want.
If you want to use the MSD Pro Billet distributor without the vacuum advance, you will need this one:https://www.summitracing.com/parts/msd-8546/overview/make/dodge
This distributor will require an amplifier ie MSD 6AL to work; no internal amplifier, just a magnetic trigger only, just like the MOPAR distributor.
The main advantage for using a MSD distributor is the ease of adjusting the advance curve and timing advance for modified engines IMO. The MOPAR distributor can connect to the MSD 6AL as well to take advantage of the multiple spark discharge. I would use a matching MSD ignition coil to avoid any issues.