I'll try to make this short...

I've got a '78 F150 4x4 that was a factory 400/4-spd truck.
I had a 429 laying around and decided to have it built (with 460 crank & pistons). The engine was in front of an automatic, so I had no flywheel to go with it.

I didn't have the funds for a $300 flywheel, so I bought a 390 'wheel off of a friend, had it machined, balanced, and a 184 tooth ring put on it. The clutch that's in it is for a Galaxie or some-such car with a 390.

I fought for a while to get the clutch linkage to where it would work properly. It seems like there are different clutch forks, and mine didn't want to stay on the throw-out bearing. The adjustment is backed all the way in (or out...however you want to look at it), so that all of my clutch movement is in the top 2" of pedal travel.

After getting the truck on the road (poorly tuned I might add), I noticed immediately that the clutch would slip some in 4th gear. Tonight on my way home from work, I decided to get on it a little bit. I grabbed 4th gear and the engine raced up to 5000rpm like it was in neutral. Then the smell of burning clutch filled the cab. I think the flywheel is now warped, as I noticed a lot of shuddering when backing around my driveway.

I'm done with it. It's all coming out and I need to do it right. I want this thing working like factory.

What do I need?

The flywheels on Summit are either the wrong tooth count, or the Hays brand is thicker and I'll need a spacer between the bellhousing (really don't want to do this)

Can I go with a 12" clutch/flywheel from a newer 92-97 truck with a NP435? Is there enough room? I don't know if a stock 11" unit will hold 400+HP on 38" tires...

Ideally, I'd LOVE to throw in a ZF5.

And keep in mind, there are NO junkyards around here with Ford trucks in them. I've been looking for 10 years.

 

No such thing as "like factory." 429's were not installed in F100/350's and 460's were not available with 4WD and a M/T until 1983, and then only in F250/350's.

1983/97 F250/350 460's came with a hydraulic clutch.

All 1965/76 FE flywheels have a 184T ring gear. 1958/64 FE flywheels have a 153T ring gear.

The only difference between a 1965/76 352/360 flywheel (C5AZ-6375-K) and 390 flywheel (C5AZ-6375-L) is the size of the clutch.

352/360: 11" clutch on a 12 3/8" bolt circle / 390: 11 1/2" clutch on a 12 7/8" bolt circle. These 2 flywheels were also used in 1965/71 352/390 Galaxie/LTD's.

 

You should be using the same fork. How did you check the free play ? How much free play was there ?

 

Me and another Dodge Guy we called Mord did a similar swap back in 1980 on a 76 High Boy .It had a 360 and we put in a T bird 429.I believe we used a 351m 400 bellhousing and clutch pressure plate assembly and a 351m 400 flywheel.everything went fairly well except we had so much clutch pedal pressure that we ended up shimming the pressure plate with 1/8 flat washers between flywheel and pressure plate.It still had a real stiff clutch you did not want to stop at a red light and hold the clutch pedal down very long .your leg would get tired so you put it in neutral and hold the brake .Well 3 days later this truck was a the truck pulls and took first place pulling.We may have used a 360 390 flywheel and clutch assembly being we done this 30 plus yrs ago but needless to say shimming out the pressure plate was what we did to make it work

 

I'm aware. I was wondering if a flywheel and clutch from a 83+ truck would work with my setup (mainly the Np435).



Thanks for that.

So lets say I went out and bought a new 460 flywheel. What clutch kit would I need to buy? Weren't there 2WD 460/4spd powered trucks in '79? And would it fix my problem?

The ZF swap is still buzzing in my head. Finding a donor truck will be hard...

 

I used the same fork that was in the trans. I never measured any free play. I did this just over a year ago, but just got the truck back on the road a couple weeks ago...so my memory of the finer details are fuzzy. Over the fall/winter, I did a D70 swap in the rear with disc brakes, F250 SD springs, shackle flip, and I just had a driveshaft made for it a month ago.

 

L&L.

For all the aggravation, it's worth it.

As a plus, their after sales support is top notch. That, and you get a steel flywheel, not a parts store cast iron wheel, and a much more left-leg-friendly diaphragm clutch.

 

1983: First year 460 available with M/T & 4WD. See flywheel (6375) applications listed below.

 

You need to take the spring back off and screw the adjuster in till you have a little play between the fork and adjuster. How much depends on where the pedel will return. imo, it's not the best designed clutch linkage in the first place. What did you use for a pilot bushing ? You can't use the needle bearing style or the fat bushing. You have to use the skinny bushing for clearance, otherwise the input shaft will bind and always be turning making it difficult if not impossible to shift. Someone in the 335 section did the ZF swap, it was quite involved as I remember.
The flywheel you have will work, plenty of people use the FE. There is something else wrong here.

 

I heard something about L&L on the search I did. I'll look into them.


OK, the adjustment is as you described. It seems like the the fork is too far forward in the bellhousing compared to what I'm use to. Meaning, the throwout bearing is closer to the engine in relation to the hole in the bellhousing that the fork passes through. It might be fine, but when the factory 400 was in there, my remembering is that the clutch fork was more perpenicular to the trans instead of the "\" angle it is at now.
The clutch pedal and travel itself is fine for my tastes. It's easy to shift, but all of my clutch action is in the upper half of the pedal's travel...instead of throughout the whole travel like you'd find on, say, a new truck.
I used the fat, solid pilot bushing provided in the kit I bought.

My biggest issue, is that my clutch is not holding the power. When I go back in to replace it, I'd like to do it right (if there is a right way)