Ok here's a question for the panel. My F-600 has a 330ci FT mated to a Clarke 285V 5spd gearbox. If I want to put in a 7.3l IDI diesel would the two mate up easily with an adapter plate and what should I do about a flywheel/clutch? I am trying to understand "dual mass" flywheels and wonder if that would be something I would want to add? Could I conceivably use the clutch I already have or would I even want to? I do not want to change the gearbox either btw.

Sorry if this is an older topic but thought I'd start it anew if it has been discussed a long time ago.

 

One major issue you may face is overall gearing. The 330 would turn up past 3000, maybe even close to 4000 rpms. You might have cruise rpms of 2500 or greater. Your IDI doesn't much like more than 3000 rpms, right? Check first.

As for an adapter, You need to check your input shaft length, and pilot size. You can probably use a clutch disc for the the Clark with a pressure plate on the 7.3. The issue here might be diameter--medium truck clutches tend to be larger than light truck jobs, so shop that out too.

Back to the adapter--I doubt you'll find one ready made. So, you can examine the others on the market and make your own--basically a spacer with threaded holes. Or, call this outfit. Heck, if they can marry a Seagrave V12 to a 700R in a Model A, your repower will be child's play:

Transmission Adapters

 

actually the 330 is governed to no more than 2800rpm I believe and I rarely ever get it over 2500 myself. This is no speed demon!

 

Why don't you use the ZF 5 speed that came with the 7.3? The Dual Mass flywheel used with the 7.3 was a 2 piece flywheel. Many owners have replaced it with a cheaper Single Mass flywheel. You can read all about it on the 6.9/7.3 IDI Forum on this website.

 

I have not purchased a 7.3l yet but suppose if I found one with the gearbox included I could go that route yet I like the idea of not having to touch any of the drivelines on the truck plus I hear that these Clark gears are really good gears. How would you compare them to the ZF 5 speeds? Btw, the Clark in mine I believe is not set up for overdrive at the top end but just straight ratio drive and at present in 5th gear I can get my rig up to 55mph on flat ground at only 2500rpm which is nice and quiet (relatively speaking that is)

 

If you would drive a truck with a 7.3 ZF5sp combo you would like it.
I have that combo in a 89 F-superduty (F450) it has the 5.13 gears.
It has the park brake on the back of the trans just like some of the older & bigger trucks.
The OD makes it work like a 4.10 in 5th. Shifts very smooth.

 

You are going to be doing a lot of fabrication work installing the 7.3 because the F600 originally had an engine mount under the nose of the engine's crankshaft and another on each side of the bellhousing. The 7.3 has mounts on each side of the block and another under the transmission. I would just go ahead and get the engine and transmission crossmembers out of the donor truck and use them in the F600 along with the ZF trans.

 

Clarks are good strong boxes, but slow to shift and pretty clunky. I rented a truck with a well worn Clark, and the shift throws were quite long. And it popped out of gear under load. ymmv on that, but the ZF is a bit smoother and tighter in the shifting dept.

What kind of loads are you looking at?

 

not any heavy towing loads at all...maybe 6000#

 

Since you haven't purchased the 7.3 yet .... how about a 5.9 Cummins? It has the center mount under the crank and the flywheel housing mounts bolt to the frame.
I used a 94 f700 as the donor for my 56 f600 Cummins conversion .... so it's still a Ford in a Ford.

 

well, I never really have thought about a Cummins 5.9 too much but don't have a real reason for that other that I know I can put my hands on the 7.3 IDI engines really easily and for cheap. Since there would be substantial structural mods to install a 7.3 diesel, I might start looking a little more at the Cummins engines.

I expect the Cummins would bolt up to the Clark gearbox without any great difficulty?

 

They put the 7.3 IDI in the medium duties as well. I would think there is a way to front mount them. I have this same idea, as I have several of these motors available. Looking at t them, I don't think it would be too hard to fab a mount using the front motor mount bolt and the bolt that is on the bottom corner of the front of the block.

 

I expect the Cummins would bolt up to the Clark gearbox without any great difficulty?[/QUOTE]

Yes, some of the bread trucks ran the Cummins with a Clark trans.

 

You have to get the proper adapter for the motor, but you should be able to find stock parts to work. Trick to using a 6bt is finding one that isn't so high priced. They are out there, just typically in the 1500-2500 range.