convert standard distributor to HEI
#1
convert standard distributor to HEI
I have a 1972 Cutlass with a 350'
I would like to do away with original distributor and install a HEI distributor
Can anyone tell me if this can be done.
Thanks
Mark
I would like to do away with original distributor and install a HEI distributor
Can anyone tell me if this can be done.
Thanks
Mark
#2
Sure it can be done. The simplest way is to find a used Olds distributor for the 75-80 era (probably can be a little later). You will need a new set of plug wires and then widen the gap on your sparkplugs. I put one in a 72 Cutlass I had a ran it for years. You might want to get a new cap and rotor. The distributor from a 350 or 455 will work. Some people have had good luck with the chineseum ones sold on ebay. Although you will not really gain any horsepower I think it is a great improvement. Whatever you do don't install a Pertronix conversion in you current distributor. Use the search function and you will find several thread on here concerning this subject.
#3
It can done pretty easy. It needs a full 12 volts in run and start position of the ignition switch. There is probably a 1/4'' spade in the fuse box for just this if its not all ready being used by something. You'll need new spark plug wires since hei uses a bigger diameter.
When I put mine in years ago, I went to the local parts store and got it. I just told them it was a 1975 model instead of 1971. Eventually I got an adjustable vacum advance can and some differnt weights and springs. to get to my liking.
When I put mine in years ago, I went to the local parts store and got it. I just told them it was a 1975 model instead of 1971. Eventually I got an adjustable vacum advance can and some differnt weights and springs. to get to my liking.
#4
As said above, it is a simple swap. There is a switched 12 Volt source in the center of the fuse box: a male spade terminal marked IGN. Just connect a wire with a female spade terminal to that, run it through the firewall, and connect it to the BAT terminal on the HEI distributor.
Also as said, you'll need new plug wires for the HEI as the distributor cap terminals are different. You can use the same plugs, even with the same gap. I open mine slightly to .040" from the original .035" but that is not mandatory.
While this swap will eliminate the routine maintenance of the points distributor, there won't be any performance improvement over a properly functioning breaker point system. Been there, done that back in the 80s and saw zero difference.
My engine has a distributor from a 1977-1979 403 engine, and the only changes I made were one light and one medium spring from a Moroso HEI advance curve kit and a home made limiter for the vacuum advance canister to reduce it from 24º to 10º. Even that is not mandatory, the engine will run OK without the limiter (mine did for years).
Also as said, you'll need new plug wires for the HEI as the distributor cap terminals are different. You can use the same plugs, even with the same gap. I open mine slightly to .040" from the original .035" but that is not mandatory.
While this swap will eliminate the routine maintenance of the points distributor, there won't be any performance improvement over a properly functioning breaker point system. Been there, done that back in the 80s and saw zero difference.
My engine has a distributor from a 1977-1979 403 engine, and the only changes I made were one light and one medium spring from a Moroso HEI advance curve kit and a home made limiter for the vacuum advance canister to reduce it from 24º to 10º. Even that is not mandatory, the engine will run OK without the limiter (mine did for years).
Last edited by Fun71; December 7th, 2020 at 02:08 PM.
#6
If you wish to keep the stock look and advance mechanism with your current distributor you may want to contact Dave Ray at davessmallbodyheis.com. He converts points distributors to use the MSD pickup and fire an HEI module. He is still recovering from a brown recluse spider bite but recent post on his website is encouraging.
#7
To the point above, the initial timing with the original HEI center bar and weights is 18º instead of 10º that was used for the points distributor.
#8
Another option, keep the points, install a MSD ignition box. The points are still used to trigger the ignition box, but they carry such a low amount of current they will last much longer.
Obviously, the ignition box is harder to hide to that purist look, but it will actually improve part throttle drivability due to multiple ignition pulses at lower engine speed. The built in rev limiter on the 6AL box is always nice to have.
Obviously, the ignition box is harder to hide to that purist look, but it will actually improve part throttle drivability due to multiple ignition pulses at lower engine speed. The built in rev limiter on the 6AL box is always nice to have.
#10
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
I also have a 72 Cutlass S (350/350). About 12 years ago I changed it from stock distributor to HEI. As others have noted you'll need to change plug wires and adjust your timing. Maybe open up the spark plug gap too; somewhere around .045 (stock is .035) since the HEI will burn somewhat hotter. My car has 16° of advance timing and it likes that. Runs very well and smooth.
One thing you'll need to consider - and I never did till after everything was done - your air cleaner setup. IF you plan to keep the stock look under the hood you'll have to modify your air cleaner to fit. The HEI has clearance issues at the back of the cleaner. I opted to cut my OEM cleaner and used some metal tape to cover the hole, then painted it black to blend in. You'd have to take off the cleaner to notice the mod.
Overall I'm pretty happy with the way the car runs although I kept the OEM distributor and all NOS replacement parts in case I want to swap back.
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