just put in my 3.54 gears!

[bryant2482]

went from a 3.89 to a  3.54. what a huge difference its made! no more quick shifts and high rpms!

[wayno]

went from a 3.89 to a  3.54. what a huge difference its made! no more quick shifts and high rpms!

3000rpms at almost 80mph, it's nice if you have the torque to get it moving.

[darrel]

Do you want a cookie?

[JoeCool]

I wouldn't mind lower RPMs and less screaming from my engine on the highway. Good idea!

[Z-train]

3000rpms at almost 80mph, it's nice if you have the torque to get it moving.

Ding-ding-ding!!!

 

Everything is a trade off.The engineers didn't put those hears in there just for shits & giggles.Rule of thumb is that for every 10 % increase in HP,you can have an equal reduction in gear ratio.

[datzenmike]

The Z24 has monster torque at just under 3K .... about 30% more compared to the L20B at slightly higher rpms. Somehow Nissan managed a 3.364 in a 2 liter 720.  But it must be pig sluggish to drive.

 

Depends what you want. This will lower the rpms but may drop them well below peak torque at highway speeds or limit how fast you can go on the highway. Even worse if windy or up hill. You will have to press the gas pedal more and more to get the same speed.

 

My 620 with 4.375 diff and stock 23.65" tall tires is changed to 33" tires. The larger tires effectively change the ratio to 3.135. My diff broke and all I had were 4.11s. This dropped the ratio to 2.945.  It will just do 60 MPH on the highway and if windy or slight up hill I have to drop into 4th right away or it will drop speed so much that only 3rd will stop it and hold the speed. This was with my L20B. I've since swapped a Z24 in it and this accelerates better in town but haven't driven it much out on the highway. I wish I had a 4.375 or better yet a 4.625. This would bring the total ratio up to 3.31. This may be why I got tired of my 620.

[bryant2482]

well i use to hit 80 on the freeway with my 3.89 at 3100 rpm np. plus i have smaller tires, about 2.5 inches smaller then stock. so it kinda evens its self out. the acceleration is great, np's with that at all and if i feel like im losing power i just shift into a lower gear

[wayno]

The Z24 has monster torque at just under 3K .... about 30% more compared to the L20B at slightly higher rpms. Somehow Nissan managed a 3.364 in a 2 liter 720.  But it must be pig sluggish to drive.

 

Depends what you want. This will lower the rpms but may drop them well below peak torque at highway speeds or limit how fast you can go on the highway. Even worse if windy or up hill. You will have to press the gas pedal more and more to get the same speed.

 

My 620 with 4.375 diff and stock 23.65" tall tires is changed to 33" tires. The larger tires effectively change the ratio to 3.135. My diff broke and all I had were 4.11s. This dropped the ratio to 2.945.  It will just do 60 MPH on the highway and if windy or slight up hill I have to drop into 4th right away or it will drop speed so much that only 3rd will stop it and hold the speed. This was with my L20B. I've since swapped a Z24 in it and this accelerates better in town but haven't driven it much out on the highway. I wish I had a 4.375 or better yet a 4.625. This would bring the total ratio up to 3.31. This may be why I got tired of my 620.

 

I have a set of 4.625 gears datzenmike, but they have about a 1/4" play in the pinion/ring gear, a far cry from the 1/16" play I like when I send a gearset out to someone.

I had the truck driven from Eugene, OR to my house when I bought it, the guy didn't say it made a lot of noise, he just said it was guttless, it came out of a 1980 datsun 720 4X4, actually the whole rearend(3rd member) is back there, I get lazy sometimes and don't pull the gearsets.

If your interested in it, I can pull the plug and check the gear oil, it could be bad, as I have never checked.

The front gearset went to dirttrack510 for one of his 510 track cars.

If the oil in it is good and you want it, I can bring it to Canby.

I also have a set of 4.37s, and they are good.

I have something I know you would want, a dually rearend with 4.625 gears, but I have to keep that for the work truck.