Mr Grady, I can't offer Wes or Don like precision (or the precision you offer) but one thought that comes to mind............ though a converter is locked (it locks in 3rd and OD as I recall), it can be slipping................ such an event could be throwing off the numbers a little.
The DLing folks can see converter slip as I recall. You'd think a converter at steady-state cruise wouldnt slip but if it's got an issue, a viscous coupling is a slippery animal.
I would post up some info. But to be honest, I've changed up my combo so much this past year. I don't remember any of the numbers. I do know going to the 3,200 stall and the 331 my cruising down the highway rpms stayed about the same and I got very surprising gas consumption results. I was pleased at making the same trips and not using much if any more gas. I can't give you mpg as my speedo has never been correct. BUT I just went to 3.55s so I should be able to dial the speedo in now.
Thanks for the info
even though you live on the wrong side of the Red River
A little local humor all you Yankees most likely can't grasp
As for the accuracy of those little calculator programs .....
I'd think them to be accurate as the ability to arrive at a value
is nothing more than simple math.
Hey ... when I was a kid in high school ........
we had nothing easy like those programs ... so ...........
it was a pencil and piece of paper
I find it interesting how we all ask each other about rpm's at highway
cruise speeds considering most of us use the OEM tach as the
standard of measurement.
Heck Fire ...
Them things have been known to be off by as much as 700 rpm
Another thing is the tire diameter is critical to accuracy here :Word:
Yes. I have a 3.73 rear end with stock torque converter, and the torque converter will lock up in overdrive at a true 34mph or 1100rpm. If I only keep very gentle pressure on the gas pedal and accelerate slowly, the torque converter will stay locked up in overdrive from 34mph upwards. If press the gas pedal a little harder, the torque converter unlocks and the rpm increases.
At a steady true 80mph cruise (speedo reading 85) my tach reads 2600rpm.