Reply to "How to increase the power handling of a ZF? (850 newton/meters or 627 foot/pounds)"

The zf was tailored to the 1970-ish version of the 351c.

Ford tinkered with the ratios such as the 2.41 vs. the 2.20:1 first gears, in order to reduce the likeliness of waranty replacements of the ZF.

There is documentation somewhere that Ford thought it likely that 1 out of 4 ZF's would fail under waranty and as a result recommended that Pantera dealers consider stocking them in the replacement parts department.

I saw quite a few NOS still in crates being "wholesaled out" in the late '70s.

I do not think that the waranty "concern" ever quite developed as Ford expected it to?


Having said all of that, the unit is designed for an engine that produces a max of around 550ft-lbs and horsepower of about the same.

I think that obviously they can and are run with much larger capacities but I think the key with that is you need to "pussy-foot" them.

If you stay with a 5.7 liter naturally aspirated engine and somewhere around 500 hp, you are in the ball park of GOOD longevity of the unit.

Things like safety wiring and messing around with better lubes are just going to help you out.

In fact, the cable shifter adds durability to it and certainly will help with the chronic second gear synchro issue.


Other then that probably go with a T44 if you can afford one and figure out how to put it into the Pantera chassis?

I would take a guess on the cost of one at around $35,000, considering you would HAVE to get one through Holman.


The only current users that can accurately comment on the longevity would be current racers. I haven't seen any bitchin' about breaking them but they may just break so much in race situations they don't even mention the ZF's breaking.

I'll bet they all have at least one spare.