I have the MSD 6 Offroad box on my truck. I really like it. It improved throttle response very well with my carb, and also helped out with passing power, mileage, starts, and everything else they claim. Personally it is one of the best mods I have done. I also run many other MSD products because I was so happy with there stuff. Here is the full list of what I run.
MSD 6 Offroad Box
MSD Cap & rotor
MSD Super Conductor 8.5mm wires
MSD Blaster SS coil
MSD Coil wire
MSD HEI dust cover
and hopefully sometime soon I am getting the MSD adjustable timing control unit and MSD Pro-Billet distributor.