[mkeafer]

I am looking for a posi-traction for my 1964 Catalina.
What range of years will fit my car?
Thanks a lot in advance.

[63 Pontiac]

Pretty sure you'll need a 59-64 Pontiac or Olds rear. Earlier than 59 used a diff. spline on the axles.

[64catdroptop]

Also 2.69:1 - 3.23:1 will have a smaller housing than 3.42:1 & up, but if you buy it as a whole unit vs. putting 3.42 gears in, it shouldn't be an issue.

-r-

[tom s]

you mean the carrier?The rear ends are the same for all ratios.Tom

[Pmrockhead]

I have a 64 Catalina which seems to be around 2.75, measured the revolutions my self so I understand the real ratio from factory is a bit different. Anyway I want to change it to mid to upper 3’s. Can’t I just go to a reputable mechanic and have it done with after market gears? Does the current housing limit how steep I can go? If so how steep can I go? Thanks

[webfoot]

Originally Posted by Pmrockhead

I have a 64 Catalina which seems to be around 2.75, measured the revolutions my self so I understand the real ratio from factory is a bit different. Anyway I want to change it to mid to upper 3’s. Can’t I just go to a reputable mechanic and have it done with after market gears? Does the current housing limit how steep I can go? If so how steep can I go? Thanks

Probably a 2.69. Per the above, it sounds like you can go up to the 3:23 in the same carrier.
Fabcraft metalworks is a good source of these, and he could tell you exactly what you can and cant do with these carriers.

https://fabcraftmetalworks.com/contact-us/

[Pmrockhead]

Would I expect a notable performance in acceleration got from the 2.69 to 3.23. Or not worth spending the $

[mgarblik]

I will try to give you a little direction. The 9.3" drop out rear end ended it's use in 64. Olds and Pontiac. Parts are very limited new. Really only one source I know of which is Fabcraft Metalworks. Take a look on their web site and you can see what's available and the prices. You may be shocked. The 9.3" is a very stout and strong rear, especially with aftermarket axles. Probably as strong as a Ford 9" which everyone loves to compare to. I just rebuilt my 62 rear with all new parts and a posi unit and a 3.42:1 gear. I had just a tick under $1500.00 in parts from Fabcraft to do it. Provided my own labor. So it's an expensive deal. I am in Ohio and I see you are as well. PM me if you are interested in having me rebuild it for you. You would need to remove the case from the housing and bring it to me. Happy to help you if you want to go that direction. A complete used unit is an option and I saw a few in the for sale section. A Ford 9" conversion is another option. They are all going to cost about the same. BTW, I am happy with my 3.42 ratio in my Catalina. Strong acceleration with 27" tall tires and around 3000 RPM's at 70 mph. Overdrive would be nice but not in the budget right now. Good luck with your decisions.

I see I made a mistake and the OP is in IL. Sorry. Still if I can help, PM me.

[tom s]

FYI!Fabcraft sold all the 9.3 stuff to J&S gear in Huntington Beach CA.Tom

[misterp266]

Fabcraft is still selling 9.3 stuff out of WY. Not sure who owns it now. Brad still sells some stuff from before he sold the business out of TX. He is 4speed427 on eBay.
I would say that a switch from a 2.69 to a 3.23 would not show enough improvement to make it worth while. I would go to at least a 3.42 as Mike did.
I ended up putting a 4.10 in my ‘63 Safari but I will be using a Richmond 5 speed with overdrive to compensate plus a 28” tire.

[stevep]

I am bringing a 3.42 single track and a posi to Norwalk to sell.