The Ford Barn

satfix · 11-06-2020, 08:02 AM

I have a 52 F1 - After taking time to investigate and figure out what rearend is in the truck, I've determined it is the original Dano 44 with a 3.92 gear ratio. (found tag: W 47/12)

Here's my question - if I want to get better highway speeds and lower the RPMs on my motor, can I change this out for a lower ratio differential? I'm ok running 65 mph, but that equates to about 2900 RPM on my 239. I'd like to be able to run under 2000 RPM for highway.

I've researched changing the transmission, but it's not a can of worms, I want to open. It'll mean major modifications and I'd rather keep the 239 Flathead with 3 on the tree intact.

If I changed the gear ratio, it would be easier to take it back to stock in the future as well.

Thoughts? Am I chasing a rabbit or is this a possibility?

Thanks

11-06-2020, 08:02 AM	#1
satfix Member Join Date: May 2020 Location: Columbia SC Posts: 31	Rearend Question I have a 52 F1 - After taking time to investigate and figure out what rearend is in the truck, I've determined it is the original Dano 44 with a 3.92 gear ratio. (found tag: W 47/12) Here's my question - if I want to get better highway speeds and lower the RPMs on my motor, can I change this out for a lower ratio differential? I'm ok running 65 mph, but that equates to about 2900 RPM on my 239. I'd like to be able to run under 2000 RPM for highway. I've researched changing the transmission, but it's not a can of worms, I want to open. It'll mean major modifications and I'd rather keep the 239 Flathead with 3 on the tree intact. If I changed the gear ratio, it would be easier to take it back to stock in the future as well. Thoughts? Am I chasing a rabbit or is this a possibility? Thanks