Took my 7.3 1991 f350 DRW CC out for a nice ride today, went from bensalem pa to staten island NY, at my office now, ran great

on NJ turnpike was doing about 70 at 2300RPMs , is that normal for a 4 speed with OD?

will be driving her home again in about 2 hours. will check oil to see how she did.

Thanks
Dave

 

yep mine turns 2500rpm at 75,

 

Yeah, though it's probably more like 2500RPM.
This is why people put 3.55 gearing or GVODs in these, if doing a lot of 70mph cruising -- NA, you lose MPG at those RPMs.

 

If you haven't checked yet, being an F350 and having the OD it's more than likely a 4:10 rear. Those RPMs support that.

 

Sorry newbie here: what are GVOD's?

thanks
Dave

 

Gear Vendors Over-Drive. $$$

 

I think he just has a 5-speed with 4.10 gears, I've heard people call a 5-speed 4-with overdrive before. so 2300 at 70mph is right

 

With stock tires? IIRC, 60MPH is around 2150, so 70 would be near 2500. This is with a ZF-5, 4.10's and 235-85-R16s.

 

i don't think their stock tires, ill get the tire measurement tomorrow off truck.

whats IIRC?

thanks
Dave

 

If I Recall Correctly


Acronyms for Newbies

 

thanks

--Dave

 

You won't have the 5th + OD unless you have a gear vendor's unit, but with stock tires and a ZF-5 speed this is what your rpm's will be:

 

You won't have the 5th + OD unless you have a gear vendor's unit, but with stock tires and a ZF-5 speed this is what your rpm's will be:

 

is my gear ratio on a sticker somewhere in the truck?

--Dave

 

Isn't that for a 4:88 rear? Or am I reading that wrong?