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My 1930 385 engine came with a HC head on it that I believe is from 1932. One difference between this head and the original is the original requires a square distributor base with four screws holding it down, while this one has a triangular base that requires only three screws.

The problem: I can't seem to get my distributor to mount so the plug wires come out directly over the port in the plug wire manifold. Looking down from above (facing forward) the wires come out at about 10 o'clock instead of at 9:00 the way they are supposed to. I've tried various positions of the distributor base and the closest I can get is 10 o'clock.

I wonder if this is because the triangular base can only be turned and secured in 120 degrees increments, while the old base can be turned in 90 degree increments. Yet the engines that originally used this head must all have the triangular base and their plug wires are in the correct orientation. I assume the distributor shaft is also the same in the later models.

Or maybe the shape of the base has nothing to do with it. The position of the rotor is determined by the position of the shaft and the distributor head can be rotated around it. Could my distributor shaft be wrongly oriented because the gear it drops into was improperly installed?

What am I missing here?

The distributor drive shaft is driven off a gear on the cam shaft and it would be possible to install it one or more teeth out. The two gears have helical teeth allowing them to mesh with their axes at 90 deg. The gear for the drive shaft has a square hole that receives the square drive shaft. The top of that shaft has an offset slot . So there are 4 positions for the drive shaft in the gear and two for the distributor to the shaft. You can simply lift out the drive shaft and refit it in any of the 4 positions then try the distributor in either of the two positions. I don't know if that will improve your problem. Simple enough to try.

Removing or re-timing the distributor drive gear would require you to separate the crankcase from the cylinder block . That is unthinkable compared to using longer HT wires.

This all from memory some time ago on my earlier model cars but I am guessing the 740 is the same.

Thank you David for clarifying how the mechanism is set up. I shall go out and try each configuration. Hopefully one will solve the problem!

Doesn't the offset driving groove in the top of the shaft limit you to just one position there, not two?

Yes of course, I would like to say I was testing if anyone was paying attention but I just wasn't thinking.

I checked and it quickly became clear that only 90 degree changes could be made. The drive gear must have been mounted 45 degrees off when the engine was re-built. Longer plug wires will do for the short term. Later, for a more proper looking arrangement, I could have a new shaft made with the top in the proper position.

I noticed your topic, and will be soon installing a distributer gear in a 1936, 385. I haven't analyzed it much yet, but was wandering is there an installation procedure for it, so it is clocked at the right position?

Has anyone ever seen a chronological assembly procedure for a 385 like more modern engines have? I've found a little in a motors manual, and some service bulletins but not much else. thanks