Final 1st gear ratio

[qmdv]

I have a 3.25 rear end with 26 tooth LZ gears. 1st seems a bit high and was thinking of changing something. What s lower? A 3.54 rear and 26 tooth first gear or a 3.25 with 28 tooth first.

[tubman]

I hated "Word Problems" when I took high school math!

[Pete]

3.25's are for Bonneville.
If you have 150 hp or more, 3.54's will get by on the street as long as you don't get carried away with too big of tires.
If you get up around 250 hp, just about any gear combination will work anywhere.
Zephyr gears are stronger by reason they have less torque multiplication so they are a good choice. 25's are even better with a big engine.

[Zeke3]

Well, if I did the math right, the 28 tooth cluster with the 3.25 rear axle will have a lower overall gear ratio (9.165:1) in first gear than the 26 tooth cluster with the 3.54 rear axle ratio (8.213:1). I hope Pete's guidance helps with your decision.

[V8COOPMAN]

Originally Posted by Zeke3

Well, if I did the math right, the 28 tooth cluster with the 3.25 rear axle will have a lower overall gear ratio (9.165:1) in first gear than the 26 tooth cluster with the 3.54 rear axle ratio (8.213:1). I hope Pete's guidance helps with your decision.

This is why I preach so loudly and so often about choosing T5 transmission gear sets so carefully. To be clear, I advocate the Camaro close ratio gear set with a 2.95 1st gear.

Now, comparing that gear choice with that "S-10" T5 transmission that everyone THINKS they need....the S-10 likely has a 4.03 1st gear. Combine that with the average 3.78 rear end gear and you end-up with an abysmal 15.233 OVERALL 1st gear ratio. Just a little more FYI!


Coop

.

[38bill]

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I had LZ gears (26t) with a 3:54 banjo and bigger tires on my truck. I did not like the LZ gears with that combination at all, just too tall. Sold the 3spd and went to a T5.

[qmdv]

Originally Posted by 38bill

I had LZ gears (26t) with a 3:54 banjo and bigger tires on my truck. I did not like the LZ gears with that combination at all, just too tall. Sold the 3spd and went to a T5.

I have 30 inch diameter tires and a 32 roadster is much liter than your truck. My displacement is 281cu in. I am wondering how happy I would be with what you had

[38bill]

Just looked and my rear tires are listed at 28.3" dia. My flathead is a 59AB bored .08 over with std stroke. I'm no expert but I can see how the 26t would be too high with the 3:25 rear end. You stated that your current setup seems to be a bit high. I know that the LZ gears made my setup a bit high. Because of this I think I would try switching tranny gears while keeping the 3:25 rear end and see what happens.

[glennpm]

I'm quite happy with my 25T LZ gears with a 3.78/1 rearend with Columbia in my 32 roadster. I can start in 1st with the Columbia engaged with slipping the clutch as another reference point.



Glenn

[drolston]

3.25 rear with zepher gears is a bit tall in low, even for a light car. If you are making the change, go with the 29 tooth cluster. That will give you the torque you need for starting on hills and manageable idle speed in the parking lot. With the low speed issue dispatched, I think you will really like the lower rpm at highway speed.



My 284 inch engine has enough torque that I am fine with 28 tooth cluster, but if I bust the tranny, I will switch to the 29 tooth.

[qmdv]

Originally Posted by glennpm

I'm quite happy with my 25T LZ gears with a 3.78/1 rearend with Columbia in my 32 roadster. I can start in 1st with the Columbia engaged with slipping the clutch as another reference point.



Glenn

Your chart lists the ratio as 3.27. Everyone is calling out 3.25. I was told that mine is 3.27 and thought that was always correct.

[drolston]

Not sure where your 3.27 came from but my 3.25 gears had 39 teeth on the ring gear and 12 on the pinion. 39/12 = 3.25

[38bill]

Originally Posted by qmdv

I have a 3.25 rear end with 26 tooth LZ gears. 1st seems a bit high and was thinking of changing something. What s lower? A 3.54 rear and 26 tooth first gear or a 3.25 with 28 tooth first.

Your original post says 3:25.

[glennpm]

https://www.fordgarage.com/pages/rearaxleratios.htm

[qmdv]

Originally Posted by 38bill

Your original post says 3:25.

Like politicians I misspoke. Mine is a 3.27 to 1

[38bill]

No problem, close enough.

[glennpm]

gmdv, you're welcome!