Best option for HEI distributor

[punchinghorse]

Believe it or not, my newly purchased '73 K5 still has points. After just having the carb completely rebuilt, it still idles funky and misses out occasionally. The points, condenser, and plug wires look to be about 15-20 years old. I was going to upgrade to HEI anyway so it seems that now is the time. All of my previous older trucks had been upgraded before I bought them so this is my first time. I'm looking at just picking up an HEI dizzy from Jegs for $95. Would this suffice or are some brands better than others?

This is a weekend toy and I don't really care about top of the line, just want something that is high quality and will last. Engine is bone stock and will probably never see above 4k RPM, if that.

Also, is anything else needed for the swap? Jegs mentions needing a new power/tach lead, and obviously new plug wires are in order, but I figured I could just pick up that stuff at a local parts house.

 

[dremu]

As mentioned, you will need the magic plugs for the power and tach. These IIRC are slightly different, one having a plastic tab that sticks out, but if all you can get at 5PM on a Saturday is one or the other, they can be made to work with dykes and a file.

You'll also want to run a new power line to the fusebox to someplace that's hot in both Start and Run (duh ) Use a fairly heavy wire like #10 or #12, and don't mess with the original dizzy hot wire. It goes through a resistor along the way and won't give you full power.

-- A

 

[punchinghorse]

I don't have a tach, so I can just grab a power lead from AZ or someplace similar? When you say run a new power line, you're just saying that I need to connect this new power lead directly to the fusebox in a place that's hot on start and run? I haven't even looked, would the stock '73 fusebox have an "IGN" port, or did they do it another way for the points dist?

 

[diesel4me]

I'd get a stock HEI with a vacuum advance from a 74-80 Chevy,and not one of the "race" HEI's that have no vacuum advance by MSD,etc..those are only good for dragstrip use..the stock GM ones work fine,and can be had cheap at a salvage yard or swap meet..why spend money you dont have too,for something that might not suit your needs?..

The newer 81 up GM HEI's with the 5 prong EST module and no vacuum advance aren't desireable either...they need a EST control module to work too,so pass on those..


If need be,Mr.Gasket makes advance curve kits and bushings with the advance weights if they are worn or need the advance curve modified (usually not needed)...

You'll need a 10 or 12 gauge power wire that is hooked to the fuse box to a terminal that is hot only when the key is in the "ON" position...(make sure its not hot on "ACC" too,or you'll have power to the coil then too,you dont want that!)....to power the coil and distributor,dont use the original points coil positive wire as its a resistance wire, and wont deliver enough voltage to properly run the coil and distributor--HEI needs a full 12V to work right..

Your old points coil may have another wire on its positive primary terminal that comes from the small "R" stud on the starter solenoid..this was intended to give the coil 12V only during cranking to help make the spark stronger..you wont need that wire any more..

Some engines prefer having the vacuum advance hooked to manifold vacuum rather than ported,you'll have to try both and see which seems better for your driving conditions..manifold vacuum is a port located below the throttle butterflies that will have full vacuum at idle,ported is above the throttle butterflies and little or no vacuum will be present at idle..

You'll also need the plug wires for the HEI,they are larger and have different ends than point style plug wires..

 

[punchinghorse]

Dummy question here...how will I find a place on the fusebox that is hot on start and run? Is there a preferred place for this swap, or will I just have to poke around until I find one?

 

[dremu]

Dummy question here...how will I find a place on the fusebox that is hot on start and run? Is there a preferred place for this swap, or will I just have to poke around until I find one?

Pretty sure my '74 is just wired to "IGN".

If you're gonna order the HEI, order the pigtail at the same time.

-- A

 

[texlurch]

You can trace the existing hot lead back to the firewall connector, cut and splice there. The resistor section is between the firewall plug and coil.
Another option I've used, if your existing dist is in good shape, is a drop in pickup like a Unilite. Just replaces your points plate and all the rest remains the same.

 

[sweetk30]

had good luck with conversion kits for point to electronic . such as petronix and others .

some even have adj rpm limits in them .