Technical It's Spline Time

I'm reevaluating a project that has fallen off the back burner and down behind the stove. I had intended to somewhat recreate the old Mickey Thompson A/FX 1962 Tempest. Always liked that car. But someone beat me to it, and it fell down the priority list year after year.
I had gathered up a car, engine, transmissions and a narrowed Pontiac rear end, and in the last week I pretty much put my hands on every part that I had squirreled away for it.
When I dug out the housing and axles, they didn't fit my 31 spline 9.3 Olds/Pontiac 4.56 Posi third member. They appear to have 33 splines. (I just checked again, yep, 33) The O.D. is 1.410". The '60 Olds axles that I have are 31 spline with an OD of 1.318". I have heard of 35 spline set-ups and 40 spline set-ups but never a 33 spline set-up. I was told when I bought the housing and axles that it was from Henry's Machine Works and it would need a 35 spline spool. Apparently, I will need a 33 spline spool.
Has anyone heard of this 33 spline set-up? I will probably just order new 31 spline axles if the project moves forward, but I'm still curious what these are and if it was a common set-up in the '60s and '70s.

 

Does this mean your not selling it to me?. I know 33 spline is not uncommon in 9 inch rear ends but haven't spent a lot of time with Olds Pontiacs other than I know they are expensive....

 

Boy are they ever. I’ve had a bunch of stuff stashed away for some time, glad I got it when I did. I knew that I had two future projects that deserved them so I kept an eye out for stuff.
9” Ford huh? I was wondering if there was a trick involving changing to different side gears or machining truck side gears or something. Kind of like when they convert old Ford rear ends to modern axles. Maybe someone here remembers what they did. Or maybe Henry’s just made their own spools to accept Ford axles?

 

I know there’s folks on here that have done a bunch of rear end work, wait a minute, that doesn’t sound right, rear axle work. Tell me about 33 spline applications. I have extra carriers and spider gears and a good machinist friend to help me. If I knew what parts to look for.
What uses 33 spline axles?

 

This might help you.
https://www.moserengineering.com/A33CST--Custom-Length-Alloy-33-Spline-Axles.item

 

Hey thanks! I’ll give them a call and see if they know how to make the 33 spline axles work in a 9.3 Pontiac carrier.

 

I bought a swap meet Ford 9" third member and it had a spool that used 33 spline axles. Traded the spool for something normal.

 

That's what I would do.