The Stovebolt Site Forums The Shop Area Engine Shop 250 to 230 distributor difference

Will a 1965 230 points distributor interchange with a 1984 250 electronic distributor? Wanting to put the late model into the early model. Modifications, problems?

The 230 and 250 engines both use the same block casting. The distributors should swap without any problems. There might be a bit of difference in the centrifugal advance curve, but so far as bolting in, no sweat.
Jerry

Martin,
You will need to run a new wire to the HEi from the ignition switch, I believe a 10 gauge wire.

And do not use the ignition resistor and bypass wire off the starter switch if there.

Ed

Sounds like it’s a drop in and some minor wiring. May just give it a try. Thanks all.

Martin,
You could probably use a relay and connect the old wire from the coil to turn on the relay. The relay would have 12 volt directly from the battery to the distributor ,you would be using the old wire to the coil to energize the relay.

That's a very good idea, as the HEI can draw up to 15 amps or more on a cold start, and that can put quite a bit of stress on the contacts of an original-equipment stovebolt ignition switch.
Jerry

The only issue with using a relay to power the HEI is the relay. Do not use any of the Chinese junk that you see for sale on eBay and other websites. They look nice but are not durable. Use a good quality brand of relay and install it where you can reach it. Then keep a spare just in case of a failure. I have used 30 amp four pin relays with pretty good results and yes, I agree, easier on this old wiring, old style of wiring, and old ignition switches.

Wiring relays is probably what I will do. Since I’m wiring challenged, along with a few other areas, could one of you provide details. What wire goes to what terminal and so on. Read Tommy’s post, wire directly from battery? Thanks🛠

Martin,
I'll look for a schematic and see what I can find. Somewhere on Stovebolt I know there is one for headlights, It would be wired the same. The 12volts from the battery, just gets switched off and on by the relay. Its just saving the old ignition switch. Don't remember what a fuse panel looks like on a 66 impala, but if there is a blank lug that says IGN., you could run the 10 gauge wire from that directly to the HEI unit and be done with it. The small wire from the ignition switch to the coil will not support the HEI. That small wire will turn the relay off and on, if you use a relay.

👍🏻 No 66 Impala here. Working on a friends ‘64 C-10. Haven’t looked at the back of the switch yet.

Get a good 30-40 amp relay. PIN number 30 is 12 volts from the battery. PIN number 87 is the power to the hei from the 30 pin when the relay switches. PIN number 85 is your ground for the relay. Finally PIN number 86 is your trigger wire so you Want this to have keyed 12 volts from the ignition switch. You might consider installing a 10 amp fuse inline with the 30 pin. I would think 12 gauge wire for the 30 and 87 pin would be fine as that is what gm used. The 85 and 86 could be 14.

The wire harness that comes with a 60 amp relay has conductors that are larger, and the relay will last a lot longer when it's operating at a fraction of its rated capacity. The physical size of the 60 amp unit isn't much bigger than the 30. I've stopped buying 30A relays altogether.
Jerry

Martin,
I found the wiring info on stovebolt, Dragsix posted it for headlights. What he says in the above post is how you should wire it. The wire from pin # 87 should be 10 gauge to the distributor. Hope this helps.

Pin 30 and 87 should be the same size wire, 10 or 12 gauge. No use feed a big wire with smaller wire!