59 AB vs 8BA Timing gears

[Mark in MT]

Here is a question for all the V8 experts. I am putting together a 59 AB with a 4" crank, and am wondering what timing gears to use. Will be using a NOS 59 AB camshaft and 46 Mercury distributer. I see that the 59 AB and the 8BA have different part numbers in the catalog, but I don't know what the difference is. Is it a physical difference, or a change in valve timimg. I have a couple very nice used sets available and don't want to put the wrong ones in. Thanks for your input.

[Ken/Alabama]

Use the one for the 59A . The teeth are cut to make the cam thrust toward the block. The 8BA thrust toward the front,dont really know why they changed but thats the difference.

[Mac VP]

Ken is correct....use the 1935-48 timing gears (together: the steel crank gear and the camshaft fiber/aluminum gear) since you are using a 32-48 type front mount distributor with its matching timing cover.

[JWL]

As mentioned by the others, your combination of components calls for using the 59A timing gear set. The distributor change between the 8BA and the 59A is why the gear sets were changed. The 8BA needs the forward thrust gear set in order to maintain proper centering of the screw gear drive of the 8BA distributor.

Yes, I know the 8BA distributor drive will work when the gears are not centered but, no engineer would design such a system.

[Richard]

good information, i am building a 59 a as well. 8ba style engines are cool too.

[JM 35 Sedan]

If you go with a fiber timing gear on the cam, make sure you get a good quality USA made part. I bought an early style press on type fiber gear from one of the well known old Ford parts suppliers, that was made in the big Asian country, and it failed on my '35 fordor in less than 1,000 miles. I replaced that failed gear with an aluminum press on gear and that has run well for the last 12,000 miles. The aluminum gear that I installed makes less noise than that junky fiber gear that it replaced.

[Richard]

I like the asian stuff but make sure its a good reproduction.

[BUBBAS IGNITION]

Neat thread !! When i first started making our chevrolet conversion i looked this gear placement over pretty well and measured up all the timing covers made for the flathead.
Most distributors ( Chevrolet , Ford etc)are designed so that the thrust is downward ( not up ward) and the drive gear is placed just slightly below the centerline of the cam drive gear.
Thats where we put everyone we build and it has worked very well with almost 700 units driving down the road....

[Mark in MT]

Thanks to all for the info, I will go with the 59 AB units.