1966 f100: 3.54 to 3.00 Ring & Pinion
 

Hello,
I'm looking for better highway top speed and want to swap my stock 3.54 ring & pinion gears for 3.00. However, my mechanic says the new 3.00 gears from Motive Gear (from Summit Racing) won't fit (too small). Will you guys give me a second opinion? And if he is right, then is there an alternative source that will work?
Thanks,
Edward

Attached are pictures. Differential tag states: "C6Ta-AY 3.54". I just had the 352 rebuilt and the 4 speed tranny.

https://cimg9.ibsrv.net/gimg/www.for...90e7533d1f.jpg


https://cimg7.ibsrv.net/gimg/www.for...e5b2a55736.jpg

https://cimg5.ibsrv.net/gimg/www.for...a5e0465bec.jpg

The alternative source is the Ford 9". Many ratios are available, and the drop-out centre section makes changes easy. If your Dana with 3.54 gears has a four-pinion limited slip it is highly sought after. A swap of complete rear ends might not be too expensive.

That number decodes to the Dana 60.3 in the 1966 F100. It was one limited slip option at the time since the 9" wasn't available in LS in the trucks in those years.

I'm not positive if they can help, but give these guys a ring (no pun intended) and see what they can tell you. Make sure you tell them it is a Dana 60.3, not the average Dana 60.

https://www.ringpinion.com

Chad

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The only ratios offered for the Dana 60.3: 3.54-1 & 4.10-1.

OP should swap in a 9" .. parts are very EZ to find and there's a gazillion different ratios available.

That's interesting. I've never seen a 60-3. The 60-2 has "60-2" cast in the top of the housing in letters an inch or so tall. You can see the markings in the truck with a light and a mirror. Does the 60-3 have such numbers cast into it?
Chad: Wasn't the Dana 44 also available in a limited slip? (Not that it would help Edward too much, the best ratio is a 3.31.)

Eric - yes - I changed my post slightly to not imply that 60.3 was the only choice.

Thanks

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The only ratios that Ford offered, yes. Only ratios available? No.

While swapping to a 9" would be the cheaper option, you could install 3.07:1 gears in your current axle if you were so inclined.

Hello 1972RedNeck,
I check with Summit Racing and this was their reply: "Thank you for the email. I do not have any 3.07 ring gears listed for your axle."
I also contacted Randy's Worldwide (ring & pinion) a couple times, but haven't heard back from them.

Do you have any recommendations for where I can find the 3.07:1 gears you mentioned that will fit my truck? I'd greatly appreciate it.
Thank you!

Swapping to a 9" May or may not be a cheaper alternative. Figure in the cost of buying a new axle of unknown condition and then rebuilding it. I figure to spend 4-500 to rebuild my 60.3 if I do it myself.

You're going to have to find a used or NOS ring and pinion and then do some machine work to make it fit.

Another alternative here would be to find a 3+1 OD Borg Warner transmission, These were an option back then in pickups. If I recall the OD was electrically activated. Taller tires will also accomplish the same thing.

Borg-Warner T-85N 3 Speed Manual with Overdrive: 1965/67 F100 240/300/352; 1968/71 F100 240/300/360/390; 1969/71 F100 302.

Give National Drive Train a call as well. I just finished replacing the R&P in my Dana 44 and they were very helpful. The gal I talked to was familiar with the fact that there are 60.2s and 60.3s out there. Good luck if you do rebuild it yourself. On mine, all seemed to go well, but I could tell something isn't right as I drove around the block.

Now I have a question for all the guru's such as ND and TA455 and the rest of you. Is the 60-3 the same as the 60-2? From the pic it looks like it is on the outside, But internally would the 3:54 gears from a 60-3 work in a 60-2? And if the answer is yes. Corequality would you be willing to part with you 3:54 ring and pinion if you find another set?

The 3.54 Ring gear and pinion kit are two different part numbers so I'll go out on a limb and say that probably would not interchange.

60.2 - 3.54 Ring gear and pinion kit - C5TZ-4209-G

60.3 - 3.54 Ring gear and pinion kit - C6TZ-4209-E

Chad