Originally Posted by Ford F834

The 6.9 clutches are even less. Go to RockAuto, look up 1986 F350 6.9 diesel manual transmission parts. The LuK rep set 12" upgrade Luk07065 is $96.79. Then look up flywheels, the LuK LFW386 is $134.99. Total 231.78 plus shipping. But you will need the 6.9 bellhousing. As tjc mentioned, the 4 speed is pretty horrible for highway use. Without overdrive the poor diesel really screams especially if you have low axle gears. Mine has 4.10's and the previous owner added a gear vendor overdrive to make a 3.20 final drive ratio. 75 mph is do-able but I'm still reaching for another gear... So I'm getting a ZF plus the GVOD to off set the 4.10's. An overdrive transmission and 3.55's is another good highway combination. Just something to consider. The IDI's rev out at a lot lower rpm than a gasser so you won't be going anywhere fast with a T19.

Originally Posted by 82F100SWB

I'm a little late to the party here, but FWIW, 12" 6.9 and 460 T19 clutches are the same part, 11" uses the same pressure plate with a different diac.
The 12" center force kit is the same part between the two.