I recently rebuilt a Pontiac 455 Ho distributor for a friend. The top bushing seized to the shaft from setting. Being a rare distributor and numbers matching, I hunted down bushing to repair the damage. All was good, had new points and setting it up on my distributor machine was easy enough. It worked great up to 4000 rpm, then the spark started jumping. Jump ahead a week I was at a swapmeet and came across a guy selling NOS ignition parts. I picked up a set of Delco points and condenser for $5. Installed them in the distributor, spun it up to 6500 rpm, not one wiggle or misfire. The new points I replaced had a very weak spring compared to the Delco set, that let the points bounce at higher rpm, the 40 year old Delco's set rock solid.
My point to all this is, know what you are buying!
A clarification, the remote mount HEI coil and distributor cap for the 250's, have the same large diameter cap as any HEI, just shorter.
