ZF6 in an obs?

[benderado]

I've been thinking about all the mods I want to do to my truck as soon as i get out of school, and decided that a 6 speed would be fun. Currently I have the ZF5 in her but one more gear would help out with fuel milage. So my question is, will a ZF6 outta a '99 and up 7.3 bolt right up to an obs? This is including bolting up to stock t-case and driveshaft.

[pipelayerjdh]

If you want one more gear, the 6spd will not help. It's overdrive ratio is almost the same as the 5spd. You will be better off to look at a gear vendors overdrive unit or swapping to higher ratio gears. What gear are you running now?

[benderado]

Right now, my best guess is 4:10's and that just based off the fact that I run higher RPM's at 60mph than my dads truck with 3:73's.

[forddieseltweek]

I know a guy that does a few tricks to the ZF-5 to fix that problem. I am taking my truck to him after the first of the year. He is also installing a SBC and a short through shifter.....

[forddieseltweek]

Originally Posted by benderado

Right now, my best guess is 4:10's and that just based off the fact that I run higher RPM's at 60mph than my dads truck with 3:73's.

There should be a ssticker on the front diff somewhere that tells you the ratio, There is on mine.

[pipelayerjdh]

Does he sell the short throw by its self? What does he do to the tranny?

[pipelayerjdh]

Originally Posted by benderado

Right now, my best guess is 4:10's and that just based off the fact that I run higher RPM's at 60mph than my dads truck with 3:73's.

Look in the door jamb at the vin sticker. Under axle it will have a 2 digit code. Post it and I'll tell you what gear it is.

[forddieseltweek]

Originally Posted by pipelayerjdh

Does he sell the short throw by its self? What does he do to the tranny?

He changes the overdrive gear to one from a gasser ZF-5. It is supposed to drop the rpm in 5th by more then 200 rpm.


He does sell the kit, Contact Dan at 888-824-2012.

Tell him that I sent you....

[2005F250]

I've drive both the ZF5 and ZF6. The ZF6 gears are spread out better and shifting is just over all better with that extra gear. The ZF5 I'm constantly shifting and what it feels like is that I need a gear between 3rd and 4th.

[pipelayerjdh]

Originally Posted by 2005F250

I've drive both the ZF5 and ZF6. The ZF6 gears are spread out better and shifting is just over all better with that extra gear. The ZF5 I'm constantly shifting and what it feels like is that I need a gear between 3rd and 4th.

I agree, and if I run across a deal on a 6spd, my truck will have one. Even though I won't be getting a higher overdrive ratio. The gear vendors is on the list otherwise.