Curious how many of you are running ZF 5speed. What gear ratio & tire sizes are you running.

35" tires and 4.56 gears

What RPM are you running at 55mph in 4th & 65-75 in 5th. Would you consider 4.88 ?

You also need to ask what engine they have.

A 5.0L / 302 has a different RPM range for best power than a 351 / 5.8L or a 400 and then there are the various strokers.

I don't have it done yet but 34" to 35" tires (metric, next maybe?) and 4.88 is my plan.

Engine?
Explorer 5.0L or 5.0L based stroker.

351 EFI, 35's and 4.10's. That setup could cruise all day long on the Interstate with ease. But my rig is more of a crawler, and I want to go to a 37", so I may regear at some point. Or perhaps build more beefy axles in the gear ratio I need, while still maintaining the ability to travel 70+mph.

I have a 400 (modified) runs about 2400 RPM at about 72MPH with 35" tires and 4.56 gears

I can run it in 5th at 35mph - 55mph no problem, well under 1500rpm at those speeds but as mentioned because of the size of my engine it has plenty of grunt at those rpms.

4.56 seems perfect for me and my needs.

If i went to 37's I would regear to 4.88. 33's I would move to 4.10's

Thanks for the input sounds like 4.56 for a combination use is the way to go.

That's what I'd do. I'll be running 4.56 with 37s, but am planning lower t-case gears.

I am running 32s and stock gearing...doesn't help you out much but there it is.