I'm about to replace my Load-O-Matic with a later model centifugal-advance distributor that I rebuilt. I just came across an article that says that the Load-O-Matic has a 13-tooth distributor gear and the post-1957 distributors have a 14-tooth gear. It would seem like I could not just swap a 14-tooth distributor for a 13-tooth distributor; I should think that I'd also need to replace the distributor drive gear on the camshaft (which I'm not about to do.) Any thoughts on this?

Thanks.

 

I changed mine last year. You need to pull the 13 tooth gear off and put it on the new distributor. Tough to do , a press would have been nice. You need to change the oil pump and drive since the new distributor is a hex drive. Easiest part of the job. Dennis in PA

 

Thanks, Dennis,

I already have the new oil pump, and I'm waiting for the ARP pump drive. I've pulled the distributor gear off the distributor I rebuilt, so I guess I'll have to pull it off again to replace it with the 13-tooth gear.

Tom

 

The oddball Dearborn 1954 239 engines (1954 car & some early '54 truck) have the 13-tooth gear. The Cleveland 239 (later '54 truck) has the 14 tooth gear. All '55-'64 Y blocks have the 14-tooth gear. The only exceptions I can possibly think of would be the marine engines, some of which are reputed to be reverse rotation. The marine Ys I have seen were conventional.

The same distinctions apply to the large journal camshafts & the later small journal cams, respectively.

The 1954 engines of either factory, including the 256, came originally with the tang/slot oil pump drive. This has nothing to do with the tooth count per se. According to the factory shop & parts manuals, all '55s should be the hex drive, which is also used in all later engines '56-'64. There have been reports of some '55 engines having the tang/slot drive as well, but it's not clear as to whether those engines came with it (early production?) or had earlier parts swapped in by dealers using old shelf stock for repairs.

You cannot swap cam gears, and as you pointed out, you wouldn't want to, , but you can change the drive gear as needed. So, go with whatever your particular engine requires. Hope this clarifies things.

 

I forgot to mention, for some reason I had to shorten my drive by about 3/16" so the distributor would seat fully in the hole. Dennis in PA

 

Dennis,

Thanks for the "heads-up." I'll be sure to check the drive length.

Tom

 

Howdy,

I did the same thing and had to replace the oil pump too since the newer distributors have the HEX drive and older Load-O had a flat drive.


My old Load-O HAD a 14 tooth gear on it. So all I had to do is replace the oil pump to match the newer dist.(I needed an oil pump anyway)

I also put a Pertronix unit in it too!


Regards,



Rick

 

Okay, I got both the oil pump and the distributor installed this weekend, but not without a few problems. (Aren't there always?) The Load-O-Matic had a 14-tooth gear on it, so I didn't need to change that, but I did need to disassemble the Load-O-Matic to use the shaft as an oil-pump primer - lots of heat and pressure to remove the gear. The spring washer (that keeps the oil pump drive shaft in position) was too far up on the expensive billet drive shaft and could not be lowered because the hex part of the shaft was not machined far enough. This would not allow the oil pump to seat on the block, so I wound up using a billet shaft from another company. The distributor REFUSED to fit down over the new drive shaft until I relieved the end of the distributor shaft, which allowed the oil pump drive shaft to insert itself. The distributor cap for the later model distributor was different from the Load-O-Matic cap, so I pulled all the plug wires out of the old cap, and used the continuity function on my VOM to identify individual plug wires. I adjusted the distributor by eye, and the engine fired on the first crank. With the vacuum advance disconnected and plugged, I set the static ignition timing at 10 BTDC. I have not yet driven the truck to see if I get "ping" at this advance. The oil pressure is definitely better with this new pump, which I massaged internally to improve flow and optize clearances. Would you believe that the pressure relief plunger has a rod that extends right through the main discharge port of the oil pump? I thinned that considerably, and trimmed back the gaskets so that they did not partially occlude the discharge and relief ports.

 

Tom,
Just read your post (a little late to save you some heartburn tho). I think you were having problems with the oil pump shaft because ARP installs the spring washer on the wrong end of the shaft. The end that goes into the distributor is beveled to help guide the shaft into the distributor.

 

I believe you are right. I "beveled" the end of the distributor shaft to compensate.