Hello,
I have a 1975, 20R, truck. The wiring harness is fried. I will be rewiring the whole truck. I am looking to swap my points ignition system with an electronic system from a 78. I was told the 1975 distributor was a one year thing, and only a 1975 distributor will bolt to a 1975 head.
I hope this is not the case............Thoughts?

 

I've never heard that the 1975 distributor is unique nor have I ever worked on one but I believe you can just swap the guts. I swapped the guts from a 1979 electronic distributor into a unknown year 18RG distributor. I wanted the correct pick up, reluctor, and connector to plug into my ignition wiring in my 1979 Celica. From what I could see, everything about the guts were identical/interchangeable except for the advance weights which i assume were different to create a different advance curve.

 

Thanks for the reply. I just bought an electronic distributor for 35.00, I was going to risk it. The ad said 75+ distributor. You confirmed my thoughts, Thanks

 

Don’t forget you’ll need a coil with ignitor to use with that factory electronic distributor. A new ignitor can run $250.00 if you can find one.
You might want to consider a complete aftermarket ignition system. If you have deep pockets, DUI corporation makes a high end HEI setup.

 

MSD style ignition box and stock coil will work well.

 

The distributor I ordered looks like it has 2 vacuum canister/ lines. Why 2? Do I need to hook both up to vacuum, or plug one?

 

Pretty sure you can just use the top one and cap the other one

 

The "new" distributor bolted up nicely. Working on making a new wiring harness for the entire truck now. Shouldn't be too bad, I like wiring.

 

I'm about 80% done with the wring harness, but the distributor I ordered was listed as a 1975+. The distributor bolted up perfectly, and I ordered a 79 cap and rotor. The 79 cap and rotor were too small. It uses the bolt on cap, which is what I ordered. There are no numbers on the distributor, but it bolts to my 1975 motor. Going from points to electronic. What part number do I need for the cap and rotor?

 

Maybe they sent you a cap and rotor for a T-series (found in Corollas in the US) engine?

 

The larger distributor cap I needed is Advance Auto part number CAC1318. Rotor button DAA1151. Pick up coil MEA2318. Plugs Autolight 64.

 

I have a 75 (from a 20R) distributor if you want it. Sounds like you may have it sorted though.

 

Thanks Man, Got it sorted. Still doing wiring, down to the lights, then fuel system.