My car came stock with 2.73 gears. I have heard from others that switched to 3.73 gears that there is noticable difference. If I switch to 3.73 what should I expect my RPM's to run up to at 60 MPH on 26 inch tires? I am mainly looking for a quick jump off the line and increase my 0-60 time....would anyone suggest 4.10 or anything else?

 

Your rear axle ratio needs to be closely matched to the powerband of the engine and the stall speed of the torque converter. It all works together.... If you gear it too tall, it will be all out of power before the end of the 1/4 mile.... if you gear it too short (like your 2.73s) it won't perform very well at lower speeds.... So what is the setup on your car? We will need more info to recommend a good axle ratio for your application.....

------------------
1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

i agree with Matt.myself,i run 4.10's in mine.i run on a 1/8 mile track also,not a 1/4.the 4.10 has a little more off the line and on through the 60 foot mark,but the 3.73 will have a little more up on top end,that is just my opinion.later

------------------
"Let's get to it,well let's do it!"

 

With a 26" tall tire, 3.73 should be fine. It will really depend on the rest of the variables mentioned above. Going to 4.10 gear you would want a 28" tall tire. With an overdrive tranny, 3.73 and 4.10 gears are bearable on the highway but still not the best mileage.

My current diff has 4.10 gear and 28" tires. I'm going to 4.56 gears in a 9" and 29.5" tires. Mine is strictly set up for 1/4 mile only. I shift at 6400 rpm and go through the traps at red line.

------------------
Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block (times are for the current engine)

Best ET on a time slip: 11.447 altitude corrected to 10.99
Best MPH on a time slip: 119.42 altitude corrected to 124.86
Altitude corrected rear wheel HP: 493
Best 60 foot: 1.586

Racing at 3500 feet elevation with a typical race day over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

Use the calculators on this site to figure out the RPM change.

Here's the link,

https://www.thirdgen.org/newdesign/t...ulations.shtml

AJ