Delco Remy HEI firing order

[JulioK]

I am still sorting thru numerous minor issues with my 72 stepside lwb 307. Lots of work that has been done by previous owner seems to have been a little flakey so I am slowly trying reestablish proper base setup. It has a delco Remy hei and I am fairly certain that the firing order is correct but I am not sure how to confirm where #1 is on the distributor. There are no marks that I can find to indicate where #1 is. I think the wires are in proper order but possibly one position off on the distributor.

Thanks

I am new at this so cut me some slack if I said something ignorant.

[davepl]

Number one is wherever you decide to hook up the #1 plug wire. Generally it's a case of whatever make the most sense for routing the plug wires and leaving yourself enough rotational room so that you can advance and retard the timing without the distributor running into something when you rotate it.

Otherwise, however, there's no special number 1 terminal on a old setup like this. The order matters, and the alignment of the rotor at TDC vs. whatever terminal you picked matters, but you could do them however you'd like.

FWIW, the assembly manual DOES show a preferred order (not for HEI, though, if that matters).

Firing order determines which plug wire comes next, and which after that, and so on.

[71swb4x4]

This is the internet, where you don't know who knows what they are talking about, and who is actually smart. Dave is very smart, he must be because I agree with him.
As he says #1 is wherever you want it to be, or to clarify wherever the rotor is pointing when you have piston #1 at TDC.

[chiefcfd]

It is usually the terminal that is pointing to the number 1 cylinder on the block. About 5 o'clock on the cap. The only way you are going to know on your motor is: Rotate the motor to top dead center. Check the timing mark on the harmonic balancer. Then see where the rotor is pointing in the cap. Hope this makes sense to you.

[Tx Firefighter]

Indeed, you can plug number one one wherever and go 8-4-3-6-5-7-2 around from there.

However, on HEI distributors, GM did have a specific number one terminal in mind. It was the terminal that most closely pointed at cylinder number 1 on the distributor cap.

And, like 71SWB4x4 said, this is the internet, full of self proclaimed experts. However, I do have a picture I took of an original HEI wire retainer that shows GM had specific numbers molded into the plastic.

[TBONE1964]

If you want it right and do it like GM done it, whether it is an HEI or a point style, number 6 and number 5 will run parallel with the fire wall such as they do in Kevin's photo above.

I understand you can drop the distributor in and # 1 can be any where you want it but if you want it correct by way of GM assembly, then #6 and #5 will be parallel or somewhat parallel with the firewall. In my opinion, it just makes everything easier that way as far as timing range and plug wire fitment.

My .02

Thank you,
Tom

[JulioK]

This is all great info thx. What outcome should I expect if the rotor was not properly aligned? I get a gulp and a knock on the valve cover over cylinder 1 when I twist the throttle aggressively from an idle. Engine quickly recovers and runs fine at higher rpm. I don't seem to get the gulping if the choke is out (idling higher). The truck is very drive able as is.

[airdale94]

#1 is the first terminal after (clockwise) the front drivers front side screw. If you've got a knock under the valve cover I'd say you have a valve train issue.

[Daman]

I had a friend ask me to come over after he fubar ed his ignition. I pulled all the wires off the cap pulled number one plug and had him crank it over with my finger in the number one hole. We reached TDC and turned it the rest of the way so the balancer lined up. Pulled the cap to see where the rotor was and started going to work. After I had #8 wire plugged in he stopped me and said I had it all wrong. I simply said "You've been working on this for how many days? Don't ask for my help if you already know everything." I finished putting on the wires and had him start it. Fired right up. Then timed it