Pertronix Ignitor plus high voltage coil are the best ignition upgrade for a street 235/261.
You can keep your existing stock dizzy and the conversion takes about 5 minutes without any hassles.
It uses the same hall-effect magnetic trigger as the HEI and can handle a 40K coil.
A fatter spark than the ignitor delivers is only required in high compression and high rpm engines.
A converted GM HEI dizzy gives no advantage on a street 235/261 over the simpler Pertronix Ignitor upgrade.
Got one on my daily 235 for many years without any problems and will put one on my new 261 as well.
Just in case, I always carry a set of stock points in the clovebox, should the ignitor ever fail.
Can't repair a bad HEI when on the road ... much less within minutes.
