I've been pondering purchasing an HEI distributor for my Olds 425. Most of what I see for sale shows the connections on the Pass Side, and the Vac Advance on the Drivers Side? Is this how they are made now?

 

Here's an option if you want to go the essentially plug and play route - and it's a small cap so more room at the firewall.

A bit pricey but great. I've had one in use with a Blaster 2 coil for about 4-5 years now with no issues.


MSD Ignition 8529 MSD Pro-Billet Ready-To-Run Distributors | Summit Racing

 

Thanks, but that adds more confusion to my question? When did the vac advance start showing up on the Drivers Side? Is there no interference with linkage?

 

none that I recall ever having heard about on the OEM style HEI but I have heard it sits really close to the firewall.

MSD has plenty of clearance from everything on my 350 and that's with an Edelbrock intake.

Presume in either case above your experience would be similar.

 

The position of the vacuum canister is really just about anywhere it physically fits on the firewall side - you can point it at the firewall, driver’s side or passenger side to some degree. The standard (larger) size cap won’t fit with certain intake manifolds either - like the dual quad one from Offy. It fits just fine with the Edelbrock Performer though. I have 2.

Basically several of the spark plug ports can serve as #1 so it’s really just a matter of which works best on your car. I’ve been running them for a couple of decades.

Very nice upgrade over points, but you have to convert it formally since it needs a switched full 12v to the unit, you can’t just drop it in on the other side of the resistance wire. There are instructions here on CO as to how to do it.

Also you’re well advised to carry a spare HEI module in the trunk or glove box because they can die without warning. The older GM modules lasted a long time, but those available now do not seem to be engineered or built to the same standards.

Hope this helps
Chris

 

Just rotate the distributor 180 degrees and voila! The connections are now on the drivers side, and the vacuum advance is on the passengers side. Attach the plug wires so they go to the correct cylinders and all is well.

 

But the vac advance can is pointed toward the firewall........... does anyone make an OEM style with the parts in the right orientation?

 

Do you have a link to the unit you are looking at?

You could buy an OEM unit and rebuild it with quality parts, then you'd have what youre looking for.

 

If you google Oldsmobile HEI Distributor, you will find many examples of what I am referring to. Everything that comes up shows a unit built opposite of OEM.

(I ordered one that I thought would work from Rock Auto, and it has a Chevy oil pump drive - made in China)

 

What the...?

 

In case it helps, I’m using Taylor brand HEI. They work fine and if I recall they were neither cheap nor the most expensive repros…

 

Solution... Buy an original GM HEI; buy an OEM pole piece and electronics for it and keep those as spares in your trunk. The total cost will be much less than for a new unit. The watchout is that you need to check for bearing wear (the shaft will move side-to-side).

It won't have pretty colors but it will be functional and will be what most of us have reliably used for many years.

 

Look, first of all, don't pay any attention to illustrations, which are usually only "representative" (meaning the generic Chevy picture). It is IMPOSSIBLE to build an Olds distributor "backwards". The rotation of the distributor determines which way the vac advance can points. There is NO possible way to build one any other way. Be careful, however, that most big box vendors like Summit and Jegs will list Chevy distributors when you ask for an Olds application, since they assume every GM has a Chevy motor.

This is an Olds HEI





This is a Chevy HEI that comes up when you search for "oldsmobile" at Summit. Note that the vac advance points the other way due to the Chevy clockwise distributor rotation.