I won't. Just might be a few hours 'til I report back. I've got a good list of errands that I need to get done.

 

From what I've seen about 99% of v8's run around 1500 - 1700 rpms at 60 mph...

Oh well, I really need to get this fixed I guess...

 

Tire sidewall data on your truck?

Getrag trans nameplate data?

Does the sticker under the hood confirm that the differential ratio is 3.55?

 

With Getrag 238 six speed manual
and 3.55 differential gears
in sixth gear (0.79)
rpm of 2100 at 60 mph
would require 27 inch diameter tires.

If in 5th gear (1.00)
rpm in 2100 at 60 mph
would require 33.8 inch diameter tires.

Getrag 6 speed manual, model 238
used with the 3.7 V6 and 4.7 V8

1st - 4.23
2nd - 2.53
3rd - 1.67
4th - 1.23
5th - 1.00
6th - 0.79
Rev - 3.84

 

I know my truck has the 3.55.. I ordered it that way.. and my tires overall height are 29.7"

In theory, what SHOULD my tach read at 60mph?

 

OK, just back from the RPM test. Mine's running at an even 2000 RPMs, in 6th, at 60 mph.

 

The 2007 Toyota Tundra six speed auto trans drivetrain
combines a 4.10 differential gear with a 0.59 top overdrive gear
with 255/70R18 tires

The 2006 Honda Ridgeline combines a 4.53 differential gear
with a 0.53 top overdrive gear
with 245/65R17 tires

Questions every pickup truck owner should ponder:

If I want the fastest 0-60 mph time
what should my rpm be when I reach 60 mph in 2nd gear?

Does it make sense to have such a high overall gear ratio in first gear
that it just breaks the tires loose uncontrollably
if I try to launch the truck
with the engine rpms near the torque peak rpm?

If I can't launch with the engine rpms near the torque peak
am I using all that my engine can give?

What should my rpms be
as I cross the finish line of a quartermile?

If as a truck owner I don't care about quartermile acceleration
what should my rpms be in the 'real world'
at 75 mph as I accelerate onto a crowded interstate highway
from an on-ramp?

 

I think that RPM range speaks towards automatic trucks, though. My manual, and Frenchy's, it seems, averages a good bit higher at 70 mph, if we're already pulling 1900-2200 RPM at 60 mph.