3.73 for 4.11 gears swap

JCM

Joined
Mar 22, 2020
Messages
7
Location
Texas
I need to set up a rig for my college kid to use as a daily driver and want to swap 3.73s in for the 4.11s that I have now. Set up with 350 SBC, 4 speed, 33" tires, but just need to get top speed up a little to make this more usable. I'm having a hard time sourcing parts - seems like a few of the guys that were selling these (front and back) are not to be found. I already know/understand the downside of swapping out the 4.11s but for my purposes I have determined that it is the way to go. Any direction on where to source 3.73s would be much appreciated.
 

1911

chupacabra
Joined
Aug 11, 2006
Messages
7,036
Location
Parker County, Texas
3.70 was stock in '79 and later U.S. market 40's.

Georg at Valley Hybrids would be another good source.
 

pb4ugo

SILVER Star
Joined
May 8, 2006
Messages
2,719
Location
spay-lay-wi-theepi, Ohio
Earlier FJ40 came with 4.11:1 gears in the differential. In 1979 Toyota change ratios to 3.70:1. You might be able to find used stk 3rd members with 3.70's and swap them in, or you can purchase aftermarket gears to what ever ratios you want. I think if you go aftermarket youll have to source fine spline pinion flanges with the proper bolt pattern for your driveshaft.
 

JCM

Joined
Mar 22, 2020
Messages
7
Location
Texas
Thanks all! I finally stumbled upon Cruiser Outfitters website shortly after posting, and after giving them a call and emailing with tech, was able to buy a couple of master install kits as well as a couple of pairs of gears. Nice and easy. We will see how it goes from here, but looking forward to hopefully an additional 10% of top-end speed (I just don't want to think about how much each additional mph costs . . .).
 

85roktoy

SILVER Star
Joined
Apr 28, 2007
Messages
678
Location
Inlet Beach, FL
What ratio should my 77 have stock?
 
Joined
Jan 9, 2020
Messages
458
Location
NorCal
Let us know how it goes. I have a similar setup with a 327 and would like to get lower rpms at freeway speeds.
 

GA Architect

SILVER Star
Joined
Feb 14, 2014
Messages
3,836
Location
Woodstock, GA
Thanks all! I finally stumbled upon Cruiser Outfitters website shortly after posting, and after giving them a call and emailing with tech, was able to buy a couple of master install kits as well as a couple of pairs of gears. Nice and easy. We will see how it goes from here, but looking forward to hopefully an additional 10% of top-end speed (I just don't want to think about how much each additional mph costs . . .).
You will like the new 3:70's. I swapped out the original 4.11 in mine for a set of 3:70 gears. Top speed I reached, 85MPH (+/-) General cruising speed on the highway, 70MPH eazy.

1652579740097.png


Also, if you are using the OEM speedometer, it will be off when you swap the gears. I called Commercial Speedometer (916-371-5873) in Sacramento, CA to get a Correction Syncro box, and how to calculate correction ratio.

1652580042354.png
 

pbgbottle

Forum Lifer
Joined
Feb 8, 2004
Messages
5,220
Location
Cloverdale B.C. Canada
To fix speedo there are t-case speedo gear drive options also from Toyota
Cheap
 

brian

SILVER Star
Joined
Feb 7, 2003
Messages
11,700
Location
lebanon,pa
Website
www.facebook.com
You will like the new 3:70's. I swapped out the original 4.11 in mine for a set of 3:70 gears. Top speed I reached, 85MPH (+/-) General cruising speed on the highway, 70MPH eazy.

View attachment 3009099

Also, if you are using the OEM speedometer, it will be off when you swap the gears. I called Commercial Speedometer (916-371-5873) in Sacramento, CA to get a Correction Syncro box, and how to calculate correction ratio.
If i figured right, its off 25% between the 33s and 370s in place of the 411s.
This has been one of the best things I've done to it....improved daily drive ability hugely.
 

85roktoy

SILVER Star
Joined
Apr 28, 2007
Messages
678
Location
Inlet Beach, FL
So to clarify cheapest and most accessible would be a 3rd from a 60? I “need” these.
 

GA Architect

SILVER Star
Joined
Feb 14, 2014
Messages
3,836
Location
Woodstock, GA
If i figured right, its off 25% between the 33s and 370s in place of the 411s.
This has been one of the best things I've done to it....improved daily drive ability hugely.
20% was my ratio with 32's & 370's in place of the 411's.
 

Users who are viewing this thread

Top Bottom