The reason I run a Pertronix here in the UK is many of us have loads of issues with Condensors, everyone here is talking about points bieng reliable and they are, they are mechanical.
However correct me if I am wrong but 95% of condensors these days are made in China they are made with inferior grade materials designed for low ambient temperatures.
I am sure if you can find a stock of NOS condensors you will be fine.
Under the bonnet of a truck is the worse place you can put a condensor, they are subject to a huge range of temperatures and moisture levels, modern ones dry out very quickly when they get warm.
I have a Mallory points dissy on my flathead Ford and it left me on the road fiddling under the bonnet several times before I took the condensor off the dissy and mounted it via a long wire under the dash, after I fitted it under the dash it never failed, but after I swapped to a Pertronix it certainly started quicker and revved much more cleanly.
My 56 Truck will run a Pertronix but with a set of points and 2 condensors in the glove box.
Trick with a Pertronix is to use their coil, the black one not chrome and make sure the dissy is well earthed, my local dealer has sold 100's of these and most failures are down to poor earthing.
Rich