[Oldsguy]

The circumference of the distributor is larger than the old style points distributor and will bump up against the #7 cylinder runner of the intake manifold because it is a dual plane. The manifold is as low as a stock with the same basic design except the runner configuration. On the O4b that runner (#7) makes enough of a dogleg back toward the firewall that it interferes with the distributor. Remember the O4b was designed before HEI distributors were in use. I have one and can confirm this. I plan on using a Mallory distributor because it is going into my '48 and I want to stay old style. If it was going to be in a modern muscle car I would go with HEI or an upgrade kit. My 461 doesn't rev past 4500 rpm anyway so I am not so much concerned with point float, although I do realize that spark is hotter with the HEI or conversion kits. Staying old style has a price that must be paid.