Does my car have an HEI distributor? How can I tell?


I’m sure this is a dumb question…I don’t have an owner’s manual, and I don’t remember seeing anything in the Haynes manual, especially since those aren’t very specific.

Is there any way to know if my 85 Oldsmobile Cutlass Supreme w/ a 305 Chevy has an HEI distributor? I bought a fancy HEI clear, translucent distributor cap/rotor kit for my car and just thought now that I should’ve made sure I have an HEI system first…if I don’t have an HEI distributor, is there a way I can modify my current setup and use this HEI cap/rotor kit that is on its way in the mail? Any help would be appreciated.




Your Olds came with a HEI distributor when it was new. Here are 2 photos if your cap looks like the HEI photo it is HEI. If it looks like the non-HEI photo it isn’t.


Thanks dartman! Always with the helpful pictures…Mine has a somewhat different plastic cover on top from the one pictured in the HEI photo, but the actual distributor cap looks the same, with the connector on the side. So I’m guessing HEI is what I got. Feeling relieved…and looking forward to the light show :slight_smile:


No problem. I find pictures really help clarify my scattered thoughts. As long as the coil is mounted on the cap it is HEI.
I am assuming this is the cap you bought.


Yup, that looks exactly like the one I ordered. Is there a time frame that I should change the coil, or just leave it for now until (or if) it causes problems down the road?
Thanks again!


These ignitions are bullet-proof. The coils last forever. The weak link is the trigger module, which is mounted on the movable vacuum advance plate. Since this part is in constant motion, eventually, the wires break from the all the flexing and the ignition quits. Sometimes these breaks occur INSIDE the insulation right at the module and are VERY hard to detect. The centrifugal advance mechanism, the part your new rotor will mount on, tend to get corroded and stick, so clean that up and lubricate it and make sure it’s moving freely when you have the cap and rotor off.

Missing from the picture is the plastic ring that snaps down on the wires once they are installed. Try not to get the wires mixed up…


Sounds good, thanks Caddyman…lube the centrifugal advance mechanism with regular oil? Or spray it with a PB Blaster type product?
As for the wires…I hear bad things will happen if you mix those up… :slight_smile:


PB spray should work fine.