If you click on his name you have an option to send a private message. When he replies it will show up on the top right of your screen below your name where it says Unread.

But as stated, tire size makes a difference, so if he isn't running the same tire size/diameter it won't be the same.
btw. Do you have Excel?
BlackGMC was kind enough to create a file that calculates all this stuff for you. All you have to do is put in the gear size and tire size and it does the rest.
In the GM Drivetrain section there is a Sticky toward the top of the threads that says Gear/MPH/Shift Points calculator for 4L60 and 4l80. In that thread there is a zip file that contains the excel file you can use.

https://www.performancetrucks.net/fo...d.php?t=396210

BTW. It says to only change whats in red. On the right change the Black tire size to come up with the diameter thats in red. Then go back to the left and change the red factors.

 

According to your tire size your tire diameter is 28.9". My truck has 31.6" diameter tires and my rpms at 70 mph are about 2100. Your rpms will be higher than this. I also lost about 1 mpg going from 3.42"s to 4.10"s.

 

No need for an apology. Welcome to the site! We'll learn you in no time, no worries

 

i have 29" tall tires and doin 70 my rpms r about 2250. man it was a heck of a difference coming from 323 where it was around 1800 on the highway

 

With my 4.10s and 30in tires. I was about 2200 give or take a couole RPM at 70mph

 

thanks for all the help i am glad i found this web site. yall really know your ****.
the calculator is awsome
thanks again

 

Any Time.
I would have posted that Calculator sooner but forgot all about it.
You can thank BlackGMC for spending the time to create it.

 

with my stock 17's, 245/70/17? im right at 2200rpm, not bad, its not as bad as it sounds.. i enjoy the 4.11's and would never to back to anything different.

 

Yes the calc works great, I am running a 30in tire with 410's and am turning about 2200 at 70

John

 

LOL, according to the calculator, I have the potential to go 259mph at 7100 rpms in my Z71!!!